I disagree that twitter is completely self serving, less so than blogs anyway. Most people spend as much time following other people's tweets, as they do tweeting themselves. The joy in Twitter lies in having regular updates of other people's activities. Obviously tweeting yourself is a big part of it, but I think it is more two sided. Blogging is different- the majority of bloggers we have spoken to seem to devote the majority of their time to their own blog, and only spend a small portion of it following other blogs. I think this is because a blog is much more personal and so when a person creates one they want to put a lot of time and energy into it as it is an extension of themselves. Whether the blog is just photographs, or recordings of their husband sleeping... a blog reveals something about a person and the way they think. A person's twitter posts are definitely less personable than their blog posts.