With the advent of web 2.0, social networking sites (SNSs) have mushroomed. Gaining competitive advantage by retaining users in the SNS is an important issue for operators. By conceptualizing stickiness as the state of individuals’ prolong stay on the SNS, the aim of this study is to explore the process of formatting SNS stickiness in the context of Facebook from the perspectives of media richness theory, uses & gratifications (U & G) theory, and intimacy. Data was collected from the northern Taiwan University. A total of 187 questionnaires were selected for the data analysis. The results support the following conclusions: 1) the media richness provided by the Facebook website directly influences users’ gratifications, including interpersonal utility and social utility; 2) the intimacy is an important mediating variable involving in the process of formatting Facebook stickiness; and 3) Facebook stickiness is indirectly influenced by gratifications, interpersonal utility and social utility, which exerts its effect through intimacy. By integrating the theoretical perspectives of media richness theory, U & G theory with intimacy into the process model of formatting Facebook stickiness, this study provides both academics and practitioners with insight into how Facebook stickiness form and enable SNS manager to retain their users.