Tinka has a nice summary of the growth of weblog clusters (see also Torill), and a fascinating note about the ambivalence people feel about the size of their audience. If nobody is listening, why write? But, if too many strangers are listening, people feel inhibited -- a shared, private writing space can suddenly seem all too public.
Though people write about the people who read their web logs, I've been thinking lots about the people who don't read this page. When lots of readers started appearing every day, I assumed most of them were friends, family, colleagues.
That turns out not to be the case. My mother doesn't read this. (I wish she did) Neither does Linda. I reconnected with some old school friends a few years ago; we send regular newsy emails. Only one of them reads this (and he's the worst correspondent). My little sister doesn't read this.