We are interested in the ways in which posting content changes individuals’ engagement with Facebook. The study augments previous knowledge about uses and gratifications from posting on social network sites by focusing on short-term activity of contributors. Using observational data analysis of individuals’ activity on Facebook, we test hypotheses regarding the existence of feedback expectations, changes in the distribution of attention to content and shifts in decisions to interact with others. We find that contribution is associated with more active site engagement that begins hours before contribution and lasts for less than a day. In addition, our findings suggest that after posting content people are intrinsically feedback-seeking, more attentive to friends (but not others) and evaluate content from friends more favorably (in large part due to reciprocity). Better understanding of the processes behind contribution will allow for the design of social network sites that support contributors better at times of social participation.