International Journal of Multidisciplinary Research and Publications ISSN (Online): 2581-6187 68 Kharisma Yogi Noviana, Reni Shinta Dewi, and Apriatni Endang Prihatini, “The Influence of Social Media Promotions and Online Customer Reviews on Purchasing Decisions on the Shopee Marketplace through Purchase Intention as a Mediating Variable (Study on Active Students of Diponegoro University),” International Journal of Multidisciplinary Research and Publications (IJMRAP), Volume 5, Issue 11, pp. 68-75, 2023. The Influence of Social Media Promotions and Online Customer Reviews on Purchasing Decisions on the Shopee Marketplace through Purchase Intention as a Mediating Variable (Study on Active Students of Diponegoro University) Kharisma Yogi Noviana 1 , Reni Shinta Dewi 2 , Apriatni Endang Prihatini 3 1 Department of Business Administration, Diponegoro University, Semarang, Central Java, Indonesia 2 Department of Business Administration, Diponegoro University, Semarang, Central Java, Indonesia 3 Department of Business Administration, Diponegoro University, Semarang, Central Java, Indonesia Email address: novianakharisma892@gmail.com, renishinta@yahoo.co.id, apriatni_ep@yahoo.co.id Abstract— The rapid development of the internet has triggered the birth of e-commerce which encourages people to make purchases online. Shopee is one of the largest e-commerce in Indonesia and even in Asia which promotes through social media and also utilizes online customer reviews as a way to attract consumers to make purchases. The purpose of this study is to determine the effect of social media promotions and online customer reviews on purchasing decisions through buying interest as a mediating variable. The number of samples taken was 211 respondents using a non- probability sampling technique using a purposive sampling technique. Data collection was carried out using a physical questionnaire and also online. This type of research is explanatory research. This study used Smart PLS 4.0 for Windows software. The results of this study indicate that social media promotions and online customer reviews have a positive and significant impact on purchase decisions through purchase intention. These results support the theory of consumer behavior in decision-making process that includes problem recognition, information search, evaluation of alternatives, purchasing decisions, and post-purchase behavior. The limitations of the researcher are in the process of collecting data to obtain respondents with the criteria of users in this study. Suggestions for further research can be carried out in other agencies, cities, or regions and also for certain members of Shopee consumers to obtain more diverse results and update results in further research. Keywords— Social Media Marketing, Online Customer Review, Purchase Intention, Purchase Decision. I. INTRODUCTION Indonesia is considered to be one of the fastest growing internet markets in the world. Based on a report from Databoks (2022), the number of internet users in Indonesia in January 2022 reached 204.7 million people, which is equal to 73.7% of the total population of Indonesia (Annur, 2022). The rapid development of the internet triggered the birth of e- commerce which encouraged people to make purchases online. Apart from the convenience that is not bound by distance or time, buying products online is considered cheaper with the many discounts offered. The ease of carrying out the buying and selling process online has encouraged increased public buying interest (Selvira et al., 2020). According to Pardede (2016) competition in the e- commerce industry in Indonesia is currently getting tighter. The existence of e-commerce such as Shopee, Tokopedia, Bukalapak, Lazada, and others in addition to offering increasingly the same products, there is also competition for prices, customers who are shrewd in choosing to fulfill their needs and the expectations and expectations of customers are getting higher and make this a picture of the current industry. So that with the increasingly fierce competition, a strategy is needed to be able to dominate the market. Promotion strategy is a major point in business, this is done in order to get the attention of consumers. One of the promotional strategies that e-commerce can use to attract consumers is by promoting through social media. Social media promotion has given a lot of attention because 55% of advertising through social media has a higher impact than conventional advertising. Meanwhile, based on a report in 2013, it states that 90% of purchases are influenced by social media (Seo & Park, 2018). Social media promotion activities can have a positive impact where consumers can directly connect with new products, services, and brands easily (Aswani et al., 2018). The use of social media in business activities has introduced a new business model, namely "social commerce" as a facility for consumers to engage in social media promotion activities where consumers can compare products or buying and selling issues directly so that they can influence the right purchasing decision (Chatterjee & Kar, 2018). Based on research conducted by (Lukito & Fahmi, 2020) that social media promotion has a positive effect on purchasing decisions by 45.7%. Apart from social media promotions, another factor that influences consumer buying interest is online consumer reviews (Ichsan et al., 2018). Customer engagement is a critical success factor for gaining customers in recent years.