This study examines Social Impact Theory factors; normative and informational social influences, and social media commitment on the purchase decision of products advertised on Facebook. The study adopts a quantitative survey-based approach, using an online questionnaire administered to 314 postgraduate students from three purposively selected universities in Lagos State, Nigeria (University of Lagos, Lagos State University, and Pan Atlantic University). This study used descriptive statistics to answer three research questions, and regression analysis to test two research hypotheses with the aid of SPSS analytical tool, version 26. Findings revealed that normative social influence, and social media commitment had significant influences on the purchase decision on products advertised on Facebook while informational social influence did not. The study recommends that decision makers in organisations, corporations or companies should encourage Facebook advertisements as an effective communication tool. Keywords: Customers’ purchase decision, E-commerce, Facebook, Internet, Social media CISDI Journal Reference Format Ogunsola K. (Ph.D.) & Mohammed, S.B. (2022): Purchase Decision on Products Advertised on Facebook: Insights from Social Impact Theory. Computing, Information Systems, Development Informatics Journal. Vol 13 No 4, Pp 73-87. Available online at
isteams.net.
dx.doi.org