How Do Online Social Networks Grow
Online social networks such as Facebook, Twitter and Gowalla allow people to communicate and interact across borders. In
past years online social networks have become increasingly important for studying the behavior of individuals, group
formation, and the emergence of online societies. Here we focus on the characterization of the average growth of online
social networks and try to understand which are possible processes behind seemingly long-range temporal correlated
collective behavior. In agreement with recent findings, but in contrast to Gibrat’s law of proportionate growth, we find
scaling in the average growth rate and its standard deviation. In contrast, Renren and Twitter deviate, however, in certain
important aspects significantly from those found in many social and economic systems. Whereas independent methods
suggest no significance for temporally long-range correlated behavior for Renren and Twitter, a scaling analysis of the
standard deviation does suggest long-range temporal correlated growth in Gowalla. However, we demonstrate that
seemingly long-range temporal correlations in the growth of online social networks, such as in Gowalla, can be explained by
a decomposition into temporally and spatially independent growth processes with a large variety of entry rates. Our analysis
thus suggests that temporally or spatially correlated behavior does not play a major role in the growth of online social
networks.