Social networks are a prominent feature of many social media sites, a new generation of Web sites that allow users to create and share content. Sites such as Digg, Flickr, and Del.icio.us allow users to designate others as "friends" or "contacts" and provide a single-click interface to track friends' activity. How are these social networks used? Unlike pure social networking sites (e.g., LinkedIn and Facebook), which allow users to articulate their online professional and personal relationships, social media sites are not, for the most part, aimed at helping users create or foster online relationships. Instead, we claim that social media users create social networks to express their tastes and interests, and use them to filter the vast stream of new submissions to find interesting content. Social networks, in fact, facilitate new ways of interacting with information: what we call social browsing. Through an extensive analysis of data from Digg and Flickr, we show that social browsing is one of the primary usage modalities on these social media sites. This finding has implications for how social media sites rate and personalize content.
