Previous studies have identified that social influence and personal preference are two key mechanisms to understand users’ social media adoption behavior. However, whether or not these two mechanisms play equal roles under different contexts has rarely been empirically investigated. To fill this gap, in this study, we propose sociability as a criterion to classify social media and examine the determinants of usage intention across social media with different sociability. An empirical study of 118 low-sociability and 123 high-sociability social media users found that social influence factors play a more important role for high-sociability media users while attitude has stronger impacts on intention for low-sociability media users. Implications for research and practice are also discussed.