150, the Dunbar's number[1]. That is indeed the natural number for any traditional communities (villages, tribes, etc). I think an important distinction is bet

150, the Dunbar's number[1]. That is indeed the natural number for any traditional communities (villages, tribes, etc). I think an important distinction is between "real" contacts, and the people you like to read stuff from every now and then. Circles can help organizing those, and not just ensuring that information doesn't leak between your distinct friend groups. 1: http://en.wikipedia.org/wiki/Dunbars_number http://en.wikipedia.org/wiki/Dunbars_number