Consumer engagement is increasingly gaining popularity among practitioners and academics as a prominent consumer-social platform relationship construct. However, few studies have examined why consumers engage in social commerce and the resulting consequences for social platforms. The Stimulus-Organism-Response model is solicited to justify the theoretical background of this study. Based on Stimulus-Organism- Response model, we develop and empirically test a three-dimensional model of customer engagement, examining relevant antecedents and outcomes for social platforms. More importantly, we propose a research model to investigate the differences between the influence of social support and community trust on customer engagement, and the impact of customer engagement on its two consequences, one transactional (repurchase intention) and one non-transactional (stickiness) aspects. An online survey of 417 participants who had purchased products from social commerce websites conducted to empirically examine the proposed research model. The results indicate that social support has a significant, positive effect on member trust and customer engagement, whereas member trust has a positive effect on community trust; community trust and customer engagement positively affect repurchase intention. In addition, customer engagement positively affects stickiness, whereas customer engagement positively affects consumers’ repurchase intention. The findings provide an understanding of the antecedents and consequences of customer engagement and contribute knowledge to the field of social commerce that can help website administrators, marketers, and social commerce retailers develop marketing policies and communication strategies.