Daniel Lyons, the professional writer and editor who, for a time, was the blogging Fake Steve Jobs, has a column in Newsweek for everybody who ever thought they could make a living by blogging.
http://www.newsweek.com/id/183666
DogRat is a hobby. I’m not selling anything, there’s no advertising, and I have absolutely no expectation of the blog being anything more than an expense and time waster. For that matter, I don’t focus on any one thing, like the popular weblogs devoted to mining every minute bit of detail about a single subject. For me, DogRat is purely a vanity outlet.
Besides the single-subject blogs, I think the single-author blogs that work the best are the ones used to promote whatever it is the author really does for a living — cartoonists Jimmy Johnson and Scott Adams, and writers Mark Evanier and Brian Sibley, for example. Beyond those, the really big blogs, as Lyons says, “aren’t really blogs — they’re media companies that happen to feature, among other things, the work of some bloggers.”