The social Web is transforming the way information is created and distributed. Authoring tools, e.g., blog publishing services, enable users to quickly and easily publish content, while social networking sites, such as Digg, Del.icio.us, YouTube, and Facebook, may be used to distribute content to a wider audience. With content fast becoming a commodity, interest in using social networks to promote content has grown, both on the side of content producers (viral marketing) and consumers (recommendation). We study the role of social networks in promoting content on the Digg. Digg is a social news aggregator that allows users to submit links to and vote on news stories. Digg, therefore, provides a direct measure of content quality, specifically, how interesting a news story is is judged by the number of votes it receives. Digg's goal is to feature the most interesting stories on its front page. Like other social networking sites, Digg allows users to designate others as "friends...