In this paper, we consider the evolution of structure within large<br />online social networks. We present a series of measurements of two<br />such networks, together comprising in excess of five million people<br />and ten million friendship links, annotated with metadata capturing<br />the time of every event in the life of the network. Our measurements<br />expose a surprising segmentation of these networks into three regions:<br />singletons who do not participate in the network; isolated communities<br />which overwhelmingly display star structure; and a giant component<br />anchored by a well-connected core region which persists even in the<br />absence of stars. We present a simple model of network growth which<br />captures these aspects of component structure. The model follows<br />our experimental results, characterizing users as either passive<br />members of the network; inviters who encourage offline friends and<br />acquaintances to migrate online; and linkers who fully participate<br />in the social evolution of the network.
Kumar, R., Novak, J., & Tomkins, A. (2006). Structure and evolution of online social networks. In Proceedings of the 12th ACM SIGKDD international conference on Knowledge discovery and data mining - KDD ’06 (p. 611). New York, New York, USA: ACM Press. https://doi.org/10.1145/1150402.1150476