Nowadays, social media platforms are becoming an integral part of marketing strategies. Social media success is measured by consumer engagement. This new technology gives organisations new ways to communicate with consumers. To engage with consumers, the organisation created online communities. Despite their significance, there is still a lack of understanding of what keeps users actively engaged in online communities. The study investigates the influence of social media marketing activity in building brand loyalty through community engagement. Moreover, to understand community information disclosure concerns, this study determines the influence of privacy calculus on community engagement. We developed a conceptual framework using SOR, S-D logic, and privacy calculus theories. Using purposive sampling, online surveys were conducted from 465 global cosmetic brand followers on social network sites. This study found that SMMa has a massive potential to build brand loyalty and community engagement is the crucial mediator between SMMa and brand loyalty.