Digg it Up! Analyzing Popularity Evolution in a Web 2.0 Setting. Paper presented at MSoDa08 (Mining Social Data), a satellite

Abstract. The recent advent and wide adoption of Social Book-marking Systems (SBS) has disrupted the traditional model of online content publishing. Until recently, the majority of content consumed by people was published as a result of a centralized selection pro-cess. Nowadays, large-scale adoption of the Web 2.0 paradigm has diffused the content selection to the masses. As a result, the evolution of online content popularity nowadays constitutes an overly complex phenomenon involving both semantic and social aspects. Work in the era before the wide adoption of Web 2.0 mostly fo-cused on estimating web resource popularity under a web graph model. Recently, several aspects of the popularity dynamics emerg-ing in the context of Web 2.0 applications have attracted significant research interest. Here, we introduce a formalism that enables the study of the dynamics underlying the popularity evolution of online content within an SBS. Based on this formalism, we carry out a study of the diggTM popularity dynamics. Our study confirms the power law nature of content popularity in SBS, and presents new insights into the temporal aspects of popularity under the influence of the so-cial factor.