"Viral media" might really be "Tree media" - Study

Finally, someone has done it (and published it in a prestigious journal like PNAS).

Apparently, current models of information spread online have assumed the "viral" form (i.e. information spreads like an epidemic, reaching the largest audience in the fewest number of possible steps).  However, recently published work in the Proceedings of the National Academy of Sciences points to a new model that is far from the "fanning out" traditionally thought to occur.  From the article's abstract (available for free here):

Interestingly, the "fan" shape that would be expected instead resembled an elaborate tree, where >90% of the letter exchanges only had one child (i.e. they passed it on to one person at a time).  Therefore, one might infer that the social relationships online aren't as powerful as one might think (i.e. those with the most friends don't necessarily influence the most people).