People who are ‘hubs’ in social networks are not the most efficient disseminators of information.
Work in social network analysis has shown that some individuals are much better connected than others — i.e., are hubs in the SN. While it’s commonly believed that hubs play a critical role in spreading information, work by Maksim Kitsak et al. at Boston U indicates taht the importance of hubs may be overstated. What is more important is where a person is located in a SN. Kitsak et al. use k-shell decomposition to do this (a k-shell is a network pruned down to the nodes with more than k neighbours). Individuals in the highest k-shells are the most influential spreaders. See http://arxiv.org/abs/1001.5285