Social comparisons to motivate contributions to an online community

It is increasingly common for online communities to rely on members rather than editors to contribute and moderate content. To motivate members to perform these tasks, some sites display social comparisons, information designed to show members how they compare to others in the system. For example, Amazon, an online book store, shows a list of top reviewers. In this study, we investigate the effect of email newsletters that tell members of an online community that their contributions are above, below, or about average. We find that these comparisons focus members' energy on the system features we highlight, but do not increase overall interest in the site. We also find that men and women perceive the comparisons very differently.