Filter & follow: how social media foster content curation

The impact of blogs and microblogging on the consumption of news is dramatic, as every day users rely more on these sources to decide what content to pay attention to. In this work, we empirically and theoretically analyze the dynamics of bloggers serving as intermediaries between the mass media and the general public. Our first contribution is to precisely describe the receiving and posting behaviors of today's social media users. For the first time, we study jointly the volume and popularity of URLs received and shared by users. We show that social media platforms exhibit a natural ``content curation'' process. Users and bloggers in particular obey two filtering laws: (1) a user who receives less content typically receives more popular content, and (2) a blogger who is less active typically posts disproportionately popular items. Our observations are remarkably consistent across 11 social media data sets. We find evidence of a variety of posting strategies, which motivates our second contribution: a theoretical understanding of the consequences of strategic posting on the stability of social media, and its ability to satisfy the interests of a diverse audience. We introduce a ``blog-positioning game'' and show that it can lead to ``efficient'' equilibria, in which users generally receive the content they are interested in. Interestingly, this model predicts that if users are overly ``picky'' when choosing who to follow, no pure strategy equilibria exists for the bloggers, and thus the game never converges. However, a bit of leniency by the readers in choosing which bloggers to follow is enough to guarantee convergence.