[I'm way behind in blogging, trying to catch up...]
Cameron brings some data to this article in the most excellent Economist regarding some of the behaviours in Facebook. With the pointless rush for many to friend the entire online population, perhaps the most salient point is:
What also struck Dr Marlow, however, was that the number of people on an individual’s friend list with whom he (or she) frequently interacts is remarkably small and stable. The more “active” or intimate the interaction, the smaller and more stable the group.
Another interesting thing about this article. When I searched in Google for 'cameron economist facebook', it clustered the article quoting Cameron Marlow regarding Facebook in the Economist with another article in the Economist about David Cameron, leader of the Conservative Party. I understand the hit, but not the clustering. A basic understanding of Named Entity Recognition would protect the analysis from this type of error. Search has a loooooong way to go...