: Epidemic content dissemination in opportunistic social networks (OSN) has been analyzed in depth, theoretically and empirically. Most related works have studied the pairwise contact history among nodes in conference or campus environments. We claim that given the nature of these networks, this approach leads to a biased understanding of the content dissemination process. We design a methodology to break OSN traces down into “temporal communities”, i.e., groups of people who meet periodically during an experiment. We show that these communities correlate with people’s social communities. As in previous works, we observe that efficient content dissemination is mostly due to high contact rate nodes. However, we show that high contact rate nodes that are more frequently involved in temporal communities contribute less to the dissemination process, leading us to conjecture that social communities tend to limit dissemination in OSNs.