Date Added: May 2013
While various models have been proposed for generating social/ friendship network graphs, the dynamics of user interactions through Online Social Network (OSN) based applications remain largely unexplored. The authors previously developed a growth model to capture static weekly snapshots of User Activity Graphs (UAGs) using data from popular Facebook gifting applications. This paper presents a new continuous graph evolution model aimed to capture microscopic user-level behaviors that govern the growth of the UAG and collectively define the overall graph structure. They demonstrate the utility of their model by applying it to forecast the number of active users over time as the application transitions from initial growth to peak/mature and decline/fatique phase.