Twitter really feels like a broadcast / subscribe network to me. Unless you're a celebrity, you aren't getting significant interaction on there, and interaction is what I use social networks for. Whenever I log in there it is just a news feed of who made the most noise today. I can leave a witty comment and some people might see it, maybe a few more would argue against it if it's incendiary, but at the end of the day it's mostly just consuming. It leaves me wanting something more and because of that I almost never use my Twitter account.