Examining The

: Social media has revolutionized the traditional marketing paradigm, where traditional marketing communication is usually regarded as a one-way relationship between service providers and consumers. The purchase decision is the final stage of a complex consumer decision-making process. which can be influenced by various marketing stimulus, one of which is Social Media Marketing activities. Heretofore, there is no certainty regarding the extent to which the effectiveness of Social Media Marketing affects purchase decisions, especially in the healthcare industry. This study employs The Stimulus-Organ-ism-Response (S-O-R) Model to explain the role of Brand Trust (O) in mediating the influence of Social Media Marketing activities (S) on Purchase Decision (R) in the healthcare industry. The sampling technique used in this study is purposive sampling. The results of this study show that Social Media Marketing cannot directly affect purchase decisions. However, Social Marketing is proven effective in generating Brand Trust, which evokes consumers’ purchase decisions. Furthermore, Brand Trust is found to be a full mediation in effect between Social Media Marketing on purchase decisions. Thus this study substantiates the implication of the Stimulus-Organism-Response Model in the healthcare industry.

The rapid development of technology in the last two decades has caused an enormous impact on all aspects of human life.The massive technological disruption has changed the marketing landscape in the way how orga-nizations interact and maintain relationships with their consumers.Social media has revolutionized the traditional marketing paradigm, where traditional marketing communication is usually regarded as a oneway relationship between service providers and consumers.The proliferation of social media usage is supported by the development of web 2.0, which facilitates various forms of participatory interaction between users, which previously could not be accommodated by web 1.0.In web 2.0, users can generate and share User Generated Content (UGC) and interact with other users on social media (Alves, 2010).Social media has changed the role of users from passive to active in the new dynamics of the collaborative web.
Social media can create dynamics of reciprocal exchange and fusion of values between service providers and consumers (Larivière et al., 2013).This two-way interaction enacts social media as an increasingly popular marketing communication tool at every stage in consumer decision-making, from awareness to customer retention.Service providers can utilize social media to increase brand awareness, customer engagement, and brand image and ultimately help consumers make purchasing decisions (Anantasiska et al., 2021;Bilgin, 2018;Cheung et al., 2020).
The purchase decision is the final stage of the complex consumer decision-making process.However, service providers should not only focus on the final part of the customer journey.Otherwise, they have to pay close attention to each stage of the decision-making process by presenting the correct marketing exposure.It is because a complex process exists before consumers reach the final purchase decisions (Basil et al., 2013).Research conducted by Duffett (2015) and Duffett (2017) concluded that social media marketing plays an important role in influencing consumer decision-making processes and attitudes towards a brand.Furthermore, social media influences consumer shopping behavior (Ismail, 2017).Stelzner (2014) stated that in the annual social media marketing report, the main benefits of Social Media Marketing for service providers are such as increased exposure (92%) and increased traffic (80%).Furthermore, it was found that the more effort companies allocate to managing their social media marketing, the greater their perceived benefits from increased sales (Stelzner, 2014).Thus, most companies focus on marketing activities through social media such as Facebook, Instagram, and Tiktok to convey their marketing communications (Koay et al., 2021).
Social Media Marketing is one of the online marketing strategies for utilizing social media to achieve the company's marketing communication goals.(Kim and Ko, 2012) Social Media Marketing is described in 5 dimensions: interaction, entertainment, trendiness, customization, and word of mouth.Still, the results of his research conclude that entertainment and interaction are the most critical determinants of Social Media Marketing.These unique characteristics cause Social Media Marketing to be different than traditional marketing.
Social Media Marketing has been proven essential in influencing consumer perceptions of brands (Angelyn and Kodrat, 2021).It is indicated by the increasing search for specific brands by customers using social media.Compared to 2020, there was a 43% increase in consumers' use of social media to discover brands, learn about products, and make some purchases (Bedgood, 2021).Consumers require service providers to be present on social media.Furthermore, 62% of consumers agree that brands that do not have a presence on social media will not be able to survive in the long term (Bedgood, 2021).However, although there are many benefits Social Media Marketing can provide, some previous research found that Social Media Marketing does not influence customers' purchase decisions (Anantasiska et al., 2021;Haudi et al., 2022).Based on a further literature review, it was found that there is an indirect influence of Social Media Marketing on purchase decisions through brand awareness and purchase intention (Angelyn and Kodrat, 2021;Ardiansyah and Sarwoko, 2020).In addition, Social Media Marketing was found to directly influence brand trust (Delgado-Ballester, 2016;Primaskara et al., 2021).
Various studies have explored the role of brand trust as an important factor that affects purchase decisions in the social commerce context.(Hajli, 2015) explained that trust can increase consumer engagement with the brand.It escalates the brand's social presence and assists consumers in determining purchase decisions.Furthermore, Putri and Rahayu (2021) research found that brand trust indirectly affects the relationship between Social Media Marketing and purchase decisions.Based on the inconsistencies outlined, this study examines the effect of brand trust on social media marketing.In social media commerce, trust is vital in consumer decision-making (Delgado-Ballester, 2016).If consumers feel that the information conveyed by the brand is reliable and the service provider can be trusted, consumers will perceive that purchasing from service providers is less risky.Thus, this study adopts the Stimulus Organism Response (S-O-R) model to explore how purchase decisions can be influenced by consumers' internal states (Jacoby, 2002).This study uses the dimensions of brand trust in service providers based on the context of social commerce.
Indonesia is the country with the 5th largest number of startups in the world in 2022, with a total of 2,346 startups (Annur, 2022).One of them has become a disruptive breakthrough in the healthcare industry.Halodoc, engaged in health teleconsultation, provides various consultations with general practitioners and specialists, medicine delivery services, and enables consumers to have boundless healthcare access.The services provided are in accordance with Halodoc's vision to simplify healthcare services for all people across the country.
Halodoc is one of the startups that optimize the use of social media, especially Instagram, in conveying their marketing efforts to provide information related to its services.Halodoc displays a lot of information on their Instagram account, delivered by photos and videos on the Instagram feed and using the instastory feature.Halodoc often presents interactive educational content to increase the public's awareness of their health.The content presented by Halodoc on Instagram is delivered concisely but remains detailed and complete to make it more understandable.
Halodoc regularly uploads infographic content on its Instagram feed.The contents are presented in visual forms, such as photos and videos containing health-related information.The content on Halodoc's Instagram is dominated by the color "red," which conveys the company's identity.Halodoc also utilizes the use of captions for every photo uploaded on Instagram.In delivering their information, Halodoc optimizes the content in visual form rather than using text because, on Instagram, photos are the ones that will make the users stop scrolling and observing.Still, the text can increase users' engagement.Social media analysts explained that Instagram feeds with captions get higher engagement compared to photos without captions.Socialbakers, an international social media marketing firm, found that the posts with captions resulted in 41% more engagement (Mana Yang Lebih Kuat Di Instagram: Foto Atau Teksnya? n.d.) Referring to this background, both from business phenomenons and research gaps found, this research will focus on analyzing the relationship between Social Media Marketing, Trust, and Purchase decisions on Halodoc.Halodoc is an interesting object to study due to the limitations of previous research on the effectiveness of Social Media Marketing specifically for service providers.Especially, Halodoc is a telemedicine service in the health sector, which tends to require a higher level of consumer involvement in determining purchase decisions.It is because healthcare purchasing decisions are unique and very distinctive from other purchasing decisions.Social Media Marketing must be able to reflect the credibility and trustworthiness of service providers before consumers make purchase decisions more than products/services in other fields.Thus, the role of Social Media Marketing becomes essential, especially in the health industry.

LITERATURE REVIEW Stimulus Organism Response Model
The S-R (Stimulus-Response) model was first proposed by (Mehrabian and Russel, 1974), which describes a person's response to stimuli from the external environment.However, this model ignores the fact that communication is a sequential process.In the S-R model, communication is considered to be static.Humans are considered to behave (R) solely because of external forces (S), not based on their free will.Thus, the individual's mental state and internal motivation are compromised in a simplified S-R model (Jacoby, 2002).Responding to these limitations, Jacoby (2002) re-conceptualizes the S-R model into an S-O-R (Stimulus -Organism -Response) model.The S-O-R model adds up a mediating aspect of one's internal evaluation in the form of emotion/motivation, which is then called Organism (O) to be an essential aspect in the process of someone responding (R) to the Stimuli (S) (Sultan et al., 2021).Stimulus (S) influences the external environment that arouses the individual (Koay et al., 2021).Organism (O) is a person's cognitive and emotional state which can be in the form of perceptions and feelings (Jacoby, 2002;Liu et al., 2019).Response (R) is the individual's final behavioral response to the stimulus (Koay et al., 2021;Mehrabian and Russel, 1974).Various previous studies that engaged in retail and social commerce (Seo and Park, 2018;Zhang et al., 2014) found that the S-O-R model roles as a theoretical basis, that marketing stimuli (S) affect the state of internal consumers (O) which will then create a specific response (R) from consumers.Therefore, this study proposes that Social Media Marketing, which is the quality of content on social media, is a stimulus (S) that will trigger the initial external evaluation (O) of consumers in the form of trust in service providers, which then results in purchasing decisions as Response (R).

Social Media Marketing
Social media is an internet-based application that enables businesses to create and communicate value (Koay et al., 2021).In addition, Social Media Marketing also facilitates interaction and collaboration between business consumers and consumer-consumer, provides personalized recommendations, and encourages information sharing and co-creation between users through UGC (Ismail, 2017;Moslehpour et al., 2021).In addition, Social Media Marketing also makes it easier for companies to provide offers and build long-term consumer relationships (Lagrosen and Grundén, 2014).These various advantages encourage more businesses to optimize their marketing activities in Social Media Marketing.Furthermore, consumers are increasingly more engaged with major social media platforms such as Facebook, Instagram, and TikTok, has motivated businesses to create reliable Social Media Marketing strategies.However, Social Media Marketing is not only limited to Facebook, Instagram, and TikTok, but also presented in various other forms, such as a combination of blogs, user reviews, social media, website link integration, and forums (Hajli, 2015).In short, businesses are more likely to practice Social Media Marketing because of the uniqueness and cost-efficiency that is provided by Social Media Marketing.In the previous literature, Social Media Marketing can be measured using five dimensions: entertainment, interaction, trendiness, customization, and word of mouth (Kim and Ko, 2012).Meanwhile (Koay et al., 2021) measured Social Media Marketing using interactivity, informativeness, personalization, trendiness, and word of mouth.Based on the research results (Kim and Ko, 2012), it was found that entertainment and interaction are the two most important determinants of Social Media Marketing factors.Based on further literature review, entertainment and interaction are two of the foremost critical determinants of Social Media Marketing factors (Gautam and Sharma, 2017;Moslehpour et al., 2021).Thus, this study uses Entertainment and Interaction to identify Social Media Marketing.Entertainment is defined as a part of social media communication that pleases users.Entertainment is cited as an important component of Social Media Marketing that enhances participatory behavior.Furthermore, entertainment is the joy that comes from using social media.This definition of entertainment is supported by a hedonic perspective which views social media users as seekers of satisfaction and joy (Cheung et al., 2020;Cheung and Iii, 2019).Meanwhile, Interaction is social media's embodiment and unique characteristic.Social media is about sharing and interaction because social media is an online environment for having discussions and sharing opinions (Kaplan and Haenlein, 2011;Koay et al., 2021).Therefore, interaction through social media enables UGC exchange.Interaction provides visibility to a larger business because it can provide the information consumers need in purchasing decisions (Moslehpour et al., 2021).

Brand Trust
The importance of brand trust has been extensively studied by various previous studies in the marketing literature (Amron, 2018; Delgado-

Stimulus-Organism-Response (S-O-R) Model Application in Examining
The Influence of ... Ballester, 2016;Primaskara et al., 2021).Brand trust is defined as the consumer's perception of whether a brand is reliable and able to deliver what is promised, which contains a cognitive element (Delgado-Ballester, 2016).If customers have a feeling of trust and a sense of security when using a brand, there will be an intention to buy, repurchase, and even brand loyalty (Tufahati et al., 2021).Brand trust is also referred to as the consumer's mental state of relying on a brand to minimize the risk, based on the expectation that the brand will bring positive results.Trust is formed by the basic information provided by the brand, which leads to product performance.Brand trust is formed when the products/services provided always meet or exceed consumer expectations (Amron, 2018).Thus, consumers' trust in the brand reflects that a product/service can fulfill its promises to consumers.In this study, brand trust is measured using several indicators developed (Chaudhuri and Holbrook, 2001;Delgado-Ballester, 2016), such as the brand's ability to meet consumer needs, the brand ability to fulfill its promises, the brand's ability to always be reliable, and the brand's ability to give honest information.

Purchase Decision
Purchase decision involves a sequential process that consumers go through before making a decision (Schiffman and Kanuk, 2007).This process begins when consumers identify their need for a product.Furthermore, consumers are in the process of determining what, when, where, how, and from whom they will make a purchase.This process requires a complex involvement of mental and physical activity.Marketers can take advantage of this consumer decision-making process to place marketing exposure at the right time and place to provide the information consumers need, which is expected to influence consumer behavior.For example, when consumers identify a need for recognition for a particular product or service, marketers place advertisements to increase consumer awareness of the brand.(Schiffman and Kanuk, 2007) explains that consumers usually look for information relevant to products/services that will be purchased from external sources.Thus the use of Social Media Marketing becomes more relevant.Consumers also try to minimize risk in purchasing decisions (Hanaysha, 2018).In this study, Purchase Decisions are measured in several indicators developed (Hanaysha, 2018), namely feelings of pleasure to purchase certain products/services, willingness to recommend certain products/services to others, willingness to always buy products/services from the same brand, and an interest in making repeat purchases in the future.

HYPOTHESIS DEVELOPMENT The effect of Social Media Marketing towards Purchase Decision
Social Media Marketing is one online marketing strategy that utilizes social media to achieve the business' marketing communication goals.Social Media Marketing has been proven to play an important role in businesses' efforts to influence consumer perceptions of brands, and Social Media Marketing was found to influence purchase decisions (Alfikri, 2021;Angelyn and Kodrat, 2021;Ridayani et al., 2021).However, although there are many benefits that Social Media Marketing offers, some previous research did not find any influence on Social Media Marketing form purchase decisions (Anantasiska et al., 2021;Haudi et al., 2022).H1: Social Media Marketing has a positive and significant influence towards Purchase Decision

The effect of Social Media Marketing towards Brand Trust
The importance of brand trust in the marketing literature has been widely explained in various previous studies (Jakic and Wagner, 2012;Chaudhuri and Holbrook, 2001;Nurhasanah et al., 2021).Trust is formed on the basic information provided by the brand that leads to product performance.Brand trust is created when the products/services provided always meet or exceed consumer expectations (Amron, 2018).Research conducted by (Delgado-Ballester, 2016;Primaskara et al., 2021) found that Social Media Marketing can directly generate consumer trust toward the brands.(Putri and Rahayu, 2021) Purchase decision involves a sequential process that consumers go through before making a decision (Schiffman and Kanuk, 2007).This process requires a complex involvement of mental and physical activity.Marketers can take advantage of this consumer decision-making process to place marketing exposures at the right time and place to provide the information consumers need, which is expected to influence consumer behavior.Research conducted by (Amron, 2018) concluded that Brand Trust could generate purchasing decisions.Similar results were also found by (Ermawati, 2018;Nurhasanah et al., 2021), who concluded that there was a positive and significant influence on the relationship between Brand Trust to Purchase Decisions.H3: Brand Trust has a positive and significant influence towards Purchase Decision

The Mediation Effect of Brand Trust in The Relationship of Social Media Marketing towards Purchase Decision
Various studies have been conducted to determine the effect of Social Media Marketing on purchasing decisions.Although there are many benefits obtained from QMS activities, several studies did not confirm the effect of Social Media Marketing on purchase decisions (Anantasiska et al., 2021;Haudi et al., 2022).Based on a further review of the literature, it was found that there is an indirect influence of Social Media Marketing on purchase decisions through brand trust (Delgado-Ballester, 2016;Primaskara et al., 2021).(Hajli, 2015) found that trust is able to increase consumer engagement with the brand, which in turn can increase the brand's social presence, and in the end, is able to assist consumers in making purchasing decisions.Furthermore, (Putri and Rahayu, 2021)  Based on the literature review that has been carried out, a conceptual framework was built, which is presented in figure 1.It is designed to understand the relationship between Social Media Marketing, Brand Trust, and Purchase Decision.

METHOD
The population used in this study is Halodoc Instagram followers, which consists of 784,000 accounts (accessed June 2022).The sampling technique used in this study is purposive sampling, where the sample will be selected from the population with the following criteria.Fist criteria is respondents have installed the Halodoc application.Second criteria is respondents have used Halodoc services through the application at least once.Last criteria is respondents use the service for their purposes.The number of samples used in this research refers to the concept of Hair et al. (2010) which explained that the number of samples is 5-10 times the number of indicators.The number of indicators used in this study is 10.Thus the number of samples used is (10 indicators x 10 = 100 respondents).This study chooses the multiplier with the largest number (multiplied by 10).It is because the researcher wants the research results to have a high level of accuracy, indicating that the selected sample can represent the population.A high degree of accuracy can be represented by large sample size, especially if there is a wide range of variability in the population (Rangkuti, 2019).The researcher also added 10% of this amount to anticipate any limitations and errors, so the number of respondents in this study was 110.The data collection process is carried out online using the google form.The researcher sent a direct message (DM) to ever y Halodoc Instagram account's followers and redirected them to the google form link. Prospective respondents must have answered with "Yes" to their respective three questions, namely 1) whether respondents have installed the Halodoc application, 2) whether respondents have used the Halodoc application at least once, and 3) whether respondents use the service for their purposes.If the respondents who have filled in the questionnaires do not meet the three criteria, the respondent's answers will be dropped from the data processing phase.The distribution of the questionnaires will be continued until meeting the number of required samples in this study.This study uses a Likert scale of 1-5 to explain respondents' answers, ranging from strongly disagree (1) to strongly agree (5).The distribution of questionnaires began in October 2021, and the number of required samples was completed in March 2022.

Social Media Marketing
Social media marketing is measured by two (2) indicators referring to (Gautam and Sharma, 2017;Kim and Ko, 2012;Moslehpour et al., 2021), which are Entertainment and Interaction.Entertainment refers to the part of social media communication that provides joy, pleasure, and happiness to users.Interaction refers to the embodiment and unique characteristic of social media itself, such as sharing an opinion, having a discussion, and interactions on social media

Brand Trust
Brand Trust is measured by four (4) indicators referring to (Chaudhuri and Holbrook, 2001;Delgado-Ballester, 2016), which are the brand's ability to meet consumers' needs, the brand's ability to fulfill its promises, the brand's ability to always be reliable, and the brand's ability to convey honest information.

Purchase Decision
Purchase Decision is measured in four (4) indicators developed (Hanaysha, 2018), which are the pleasure of purchasing certain products/services, willingness to recommend certain products/services to others, willingness to always buy products/services from the same brand, and the interest in making repeat purchases in the future.

RESULTS
The characteristics of respondents in this study will be described based on gender, age, domicile, latest education, and the respondent occupation.Table 1 showed that some important information can be obtained, including the majority of users of Halodoc are women.It can be observed that the people of DKI Jakarta and West Java dominate the Halodoc application users in this study, referring to the residence domicile.Meanwhile, the majority of respondents in this study were high school graduates/equivalent with occupations as students.
Table 1 showed that the majority of respondents in this study have a monthly income of less than 3 million rupiah.
This study employs the Structural Equation Model -Partial Least Square (SEM-PLS) to analyze the data.Data analysis was carried out in 2 stages, namely the evaluation of the Outer Model and the Inner Model analysis.In evaluating the outer model, the analysis carried out is to test the construct validity and reliability of the research instrument.Construct validity consists of the loading factor, and the measured reliability is based on Cronbach's alpha and composite reliability.The rule of thumb used for convergent validity is to have a loading factor value > 0.60 (Abdillah and Jogiyanto, 2015).If the item does not meet the rule of thumb, then the item must be eliminated from the research model.In this study, three items must be eliminated from the research model, namely SMM3, SMM6, and Social Media Marketing 7, because they have a loading factor of < 0.06.After the three items were deleted, the outer loading value of all items was> 0.06.All variables in this study have met the rule of thumb used for reliability testing is the provision of Cronbach's alpha value > 0.70 (Hair et al., 2010).Furthermore, all the variables in this study have also met the rules of thumb used for the reliability test with a composite reliability value > 0.70 (Hair et al., 2010).Thus, it can be stated that all items in this study have met the validity and reliability requirements.

Inner Model Analysis
The second phase is measuring the Inner Model or hypothetical test results.The t-test or path coefficient is used to indicate the test hypothesis's significance level.Furthermore, the mediation effect was tested to determine the role of the mediating variable, whether it was partial or full mediation.

Social Media Marketing has a Positive and Significant influence towards Purchase Decision
The result shows that the Social Media Marketing path coefficient on Purchase Decision has a negative value of 0.118 with a t-statistics value of 0.238 and a significance level (p-values) of 0.619.Given the value of t-statistics <1.96 and p-values> 0.05, the relationship is declared insignificant, so it can be concluded that Social Media Marketing has no significant effect on purchase decisions.Thus, the first hypothesis is rejected.

Social Media Marketing has a Positive and Significant Influence towards Brand Trust
The result shows that the coefficient of the Social Media Marketing path to Brand Trust has a positive value of 0.793 with a t-statistics value of Deandra Vidyanata 13,484 and a significance level (p-values) of 0.000.Given the value of t-statistics <1.96 and p-values> 0.05, the relationship is declared significant, so it can be concluded that Social Media Marketing has a positive and significant effect on purchase decisions.Thus, the second hypothesis is accepted

Brand Trust has a Positive and Significant Influence towards Purchase Decision
The result shows that the path coefficient of Brand Trust on Purchase Decisions has a positive value of 0.975 with a t-statistics value of 4.958 and a significance level (p-values) of 0.000.Given the t-statistic value < 1.96 and p-value > 0.05, the relationship is declared significant, so it can be said that Brand Trust positively and significantly affects purchasing decisions.Thus, the third hypothesis is accepted

Brand Trust Mediates the Influence between Social Media Marketing toward Purchase Decision
The result shows that the Social Media Marketing path coefficient on Purchase Decisions with Brand Trust mediation has a positive value of 0.773 with a t-statistics value of 3.860 and a significance level (p-values) of 0.000.The relationship is declared significant, so it can be concluded that Brand Trust mediates the effect of QMS on Purchase Decision Considering the t-statistic value < 1.96 and p-value > 0.05.Thus, the fourth is accepted.

Indicect effect
Furthermore, to determine the role of brand trust as mediating variable, this analysis will be continued by comparing the value of the beta coefficient on the direct effect of exogenous variables on endogenous variables with the value of the beta coefficient on the indirect effect.
Based on the calculation, it is known that the direct effect coefficient of the Social Media Marketing on Purchase Decision is 0.663 with a significance level (0.000) <0.05, while the Social Media Marketing indirect effect coefficient on Purchase Decision drops to -0118 and has become insignificant (0.619 > 0.05).The figure shows that the effect of Social Media Marketing on Brand Trust (a) is significant with p-values of 0.000, less than 0.05, and the influence of Brand Trust on Purchase Decisions (b) is significant with p-values of 0.000, which is less than 0.05.Hair et al. (2010) Table 5 shows that the R² value for Brand Trust is 0.623, categorized as a moderate to strong model, meaning that the Social Media Marketing variable can explain the brand trust variable by 62.3%.Other variables outside the model explain the remaining 37.7%.Furthermore, the R² value of the Purchase Decision is 0.776.Thus it can be categorized as a moderate to strong model, meaning that the Social Media Marketing and Brand Trust can explain the purchase decision variable by 77.6%, and the remaining 22.4% is explained by other variables outside the model, such as brand awareness, brand image, brand preference (Anantasiska et al., 2021;Diantari and Jokhu, 2021), and brand attitude (Duffett, 2017)

Social Media Marketing towards Purchase Decision
Based on the hypothesis testing result, it can be concluded that the first hypothesis is rejected.It shows that the use of Social Media Marketing has no direct effect on consumer purchasing decisions.This result has been the opposite of previous research, which stated that Social Media Marketing activities could influence purchase decisions (Alfikri, 2021;Angelyn and Kodrat, 2021;Diantari and Jokhu, 2021;Ridayani et al., 2021).However, this result supports previous studies which stated that Social Media Marketing has no significant effect on purchasing decisions (Haudi et al., 2022;Okadiani, 2019).In this study, Social Media Marketing is measured using two indicators: Entertainment and Interaction.Entertainment is a component of Social Media Marketing that is believed to pleasure consumers in their information searching on social media.The entertainment element in social media creates an emotional connection with consumers, where forming an emotional connection can provide a brand experience (Koay et al., 2021).The entertainment aspect (ENT), which brands in social media usually present, includes games, videos, infographic presentations, contests, and games, making consumers enjoy their experience on social media more (Tuten, 2010).It can motivate consumer interaction and participation in the brand community.Social media posts with images, video clips, and story content can effectively attract consumers' attention.Thus, the entertainment aspect of social media represents the brand's ability to share interesting and exciting content (Tuten, 2010).Several items measure entertainment in this study, including Halodoc providing  All of these items emphasize the hedonic aspect of consumers when using social media (Sultan et al., 2021).Meanwhile, interaction refers to the characteristics of social media in facilitating the two-way exchange of opinions and information (Moslehpour et al., 2021).The interaction aspect can strengthen consumer attitudes towards the brand.Informative content that corresponds to the target audience's profile will encourage discussion and improve the relationship between consumers and brands.While interaction is measured with several items, making it easier for consumers to express their opinions on Halodoc Instagram, simplifying conversations with other users, easy 2-way interactions with brands, and simplifying sharing information.Regarding the interaction aspect, Halodoc often creates content through videos and Instagram stories with multiple choice features, contests, and quizzes.It is used to increase engagement.Halodoc also contains content that must be further responded to by consumers, such as "Write your experience in the comment section down below" so that users can express and share opinions with other users to increase interactions.In this study, it is found that there is no influence between Social Media Marketing on the purchase decision.That may be due to the uniqueness of the object of this research, namely telemedicine services, which are part of the healthcare industry.The consumer decision-making process regarding medical and health needs is different and more complex than other products.It is because consumers consider more internal evaluation factors before making purchasing decisions.Some of the dominant factors in influencing purchasing decisions in telehealth use decisions are knowledge, experience, trust, satisfaction, and attitudes (Woo and Dowding, 2020).It means the entertainment and interaction aspects of Halodoc So-cial Media Marketing alone are not enough to influence consumers' purchase decisions on telemedicine services directly.Furthermore, a study conducted by (Gong et al., 2019) found that trust in service providers, subjective norms, and perceived benefits were the main factors consumers considered before adopting telemedicine services.Furthermore, this result also confirms the limitations of the S-R model, which only explains that individuals behave solely based on stimuli from the environment and ignores the individual's internal evaluation (Jacoby, 2002).

Social Media Marketing towards Brand Trust
Based on the hypothesis testing result, it can be concluded that the second hypothesis is accepted.The result is in line with previous research (Delgado-Ballester, 2016;Primaskara et al., 2021;Putri and Rahayu, 2021), which stated that Social Media Marketing has a positive and significant effect on brand trust.Brand trust is critical in explaining purchase decisions (Delgado-Ballester, 2016).In social commerce, there are a lot of uncertainties and ambiguities that might occur, and consumers highly anticipate it.Thus, consumers' confidence in the brand/service provider can compensate for this feeling of uncertainty (Moslehpour et al., 2021).Therefore, brand trust is important in strengthening consumer and brand relationships.One of the Social Media Marketing aspects, interaction, is often referred to as a reinforcement of consumer confidence in the brand.It is confirmed by various previous studies regarding the role of brand trust in generating consumer purchase intention (Chaudhuri and Holbrook, 2001;Ermawati, 2018), where purchase intention was stated as the most important predictor of actual behavior (Schiffman and Kanuk, 2007).The Social Media Marketing campaign carried out by businesses must be able to develop consumers' trust in the brand.In Halodoc, Social Media Marketing activities often share entertaining content on social media, which will increase consumer excitement and extend consumer scrolling time on Instagram, increasing consumer engagement with service providers.(Tuten, 2010) explained that uploading entertaining content will benefit the organization, one of which is influencing consumer per-ceptions and attitudes towards brands to be more favorable.In addition, the regular interaction of brands through social media can assist consumers' information searching process.A study by Jakic and Wagner (2012) found that interaction is the most important antecedent of Brand Trust.Furthermore, consumer-brand interaction created consumer trust in the brand (Moslehpour et al., 2021).

Brand Trust towards Purchase Decision
Based on the hypothesis testing result, it can be concluded that the third hypothesis is accepted.This result is in line with previous studies, which concluded that brand trust positively influences purchasing decisions (Amron, 2018;Ermawati, 2018;Nurhasanah et al., 2021).One problem that often arises within online and social commerce businesses is the lack of consumer trust in the brand (Kamal et al., 2020).These dynamics may result in consumers' purchase decisions.Trust is essential in influencing a purchase decision, especially in online and social commerce (Moslehpour et al., 2021).Consumers will not make a purchase decision if they do not trust the brand/service provider.Consumer trust in the brand also shows that service providers can be trusted (Chaudhuri and Holbrook, 2001).Brand Trust indicators used in this study include the brand's ability to meet consumers' needs, the brand's ability to fulfill its promises, the brand's ability to always be reliable, and the ability to convey honest information.Consumers demand a brand that can always be trusted and perform its competence before consumers make a purchase decision.Specifically, in telemedicine and telehealth services, trust describes the faith and hope of consumers to get better health conditions.Thus, trust in service providers is important, especially in the healthcare industry.Trust is an essential condition in maintaining successful interpersonal relationships.Therefore trust has a central role in influencing the purchase decision.

Brand Trust mediates the influence of Social Media Marketing toward Purchase Decision
Based on the hypothesis testing result, it can be concluded that the fourth hypothesis is accepted.
The result of this study is in line with previous studies, which concluded that brand trust mediates the effect of Social Media Marketing on Purchase Decisions (Delgado-Ballester, 2016;Pop et al., 2022;Primaskara et al., 2021).Furthermore, this study successfully confirms the congruence of the S-O-R model in explaining the influence of social media marketing on purchase decisions.The S-O-R model enhances the limitations of the S-R model by adding aspects of individual internal evaluation (O) in behavior (Jacoby, 2002).The result of this study indicates that the Social Media Marketing activities carried out by Halodoc can indirectly influence consumers' purchase decisions through brand trust.The S-O-R model in this study implies that Social Media Marketing (S) does not directly affect purchasing decisions (R) but must be determined in advance by the existence of the consumer's inner state activity to trigger a specific response, which in this study is explained by Trust (O).It is directly shown by the inability of Social Media Marketing to influence purchase decisions, which in this case, is represented by the S-R theory.However, the Social Media Marketing activities carried out by Halodoc are proven to be effective in forming a favorable internal consumer condition (Liu et al., 2019), which includes consumers' cognition and affection in the form of Trust towards the brand.A favorable internal evaluation can encourage the establishment of purchase decisions.It is also confirmed by several previous studies conducted in the health industry, specifically for telehealth services, where consumer trust in service providers plays an essential role that can influence consumer purchase decisions (Kamal et al., 2020;Woo and Dowding, 2020).Furthermore, the result of the Brand Trust role as the mediating variable shows that Brand Trust acts as a full mediation of the effect between Social Media Marketing on purchase decisions.It can be interpreted firmly as without consumer trust towards the brand or service providers, social media marketing activities performed by the brand is not capable of affecting consumers' purchase decision.This result substantiates the implication of the Stimulus-Organism-Respons Model in the healthcare industry.SEPTEMBER 2022 Deandra Vidyanata

CONCLUSIONS
The purchase decision is the final stage of a series of complex consumer purchasing behavior, which can be influenced by various marketing stimulus, one of which is Social Media Marketing activities.Heretofore, there is no certainty regarding the extent to which the effectiveness of Social Media Marketing affects purchase decisions, especially in the healthcare industry.It is indicated by the limited previous studies that specifically discussed the role of Social Media Marketing in generating purchase decisions in telemedicine services.The results of this study conclude that Social Media Marketing can directly not influence purchase decisions.Social Media Marketing has a positive and significant effect on Brand Trust.Brand trust has a positive and significant impact on Purchase decisions.Brand Trust fully mediates the influence of Social Media Marketing on Purchase decisions.

LIMITATIONS
Although this research has been done accordingly to the research procedures, it is undeniable that this research still has some limitations.These limitations will be highlighted for improvement and refinement in future studies.The data collection process in this study took a long time because the researcher sent direct messages (DM) to followers of Halodoc's Instagram account.Most prospective respondents were reluctant to reply to DMs from unknown senders.Furthermore, there is a lot of data not processed in this study because it does not meet the three mandatory criteria.In addition, due to technical problems, one of the characteristics of the respondents, i.e., "Age," cannot be included in the discussion.

RECOMMENDATIONS
Based on this research, Brand Trust roles are critical factors that have to be fully considered by service providers in the healthcare industry, especially telemedicine services.Though Social Media Marketing is an important marketing strategy to reach more consumers in this digitalization era, it cannot function as a panacea to generate consum-ers' purchase decisions.The results of this study contribute to the marketing literature, and in particular, to service providers.Social Media Marketing activities should be developed and performed on how service providers can form consumers' trust towards the brand.It can be done by routinely uploading informative content as a soft selling strategy.In addition, providers can assign specific social media administrators to respond quickly to customers' questions, which can increase consumer attitudes and trust toward the brand.Service providers should also emphasize the image of honesty by providing reliable, informative and accurate information about the services displayed on their social media platforms.Future researchers can develop this research by testing the congruence of the S-O-R model in explaining the influence of social media marketing in different industries.In addition, further researchers are recommended to include trendiness, customization, and word of mouth to measure Social Media Marketing.

Figure 3 .
Figure 3.The Indirect Effect of Social Media Marketing towards Purchase Decision through Brand Trust

The Effect of Brand Trust towards Purchase Decision
also confirmed that Social Media Marketing SEPTEMBER 2022

The Direct Effect of Social Media Marketing towards Purchase Decision
stated that if a and b are significant, but c is not significant, then Z can be stated as full mediation.

Table 5 . Inner Model Evaluation with Coefficient of Determination R²) SEPTEMBER 2022 Deandra Vidyanata interesting
content on Instagram, Halodoc sharing a lot of useful information, and Scrolling on Halodoc's Instagram makes me lose track of time Halodoc's Instagram has a lot of entertaining content.Halodoc routinely posts useful information related to health in the form of images.In addition, the halodoc Instagram feeds, which dominantly use the magenta color, are intended to strengthen the brand image.