With the rapid advancement of the Internet of Things and information technology, alongside evolving consumer perceptions and rising expectations, the traditional social e-commerce marketing model has reached maturity. In response, a growing number of e-commerce and social platforms have integrated social interaction and commercial exchange, giving rise to the emerging paradigm of social e-commerce. This study investigates the mechanisms of social marketing in e-commerce platforms and explores strategies for enhancing their marketing effectiveness. Using Yunji Microstore as a case study, the findings reveal that the adoption of an appropriate social marketing model and the resolution of platform-specific challenges exert a significant positive influence on the sustainable development of e-commerce enterprises. Accordingly, this study recommends optimizing supply chain management, employing innovative promotional strategies, and establishing a robust customer credit mechanism to strengthen consumer trust and competitiveness within the social e-commerce ecosystem.