I've been reading several articles lately that have discussed the rise (and decline) of blogs - as far as making money from them. Basically, it's getting harder and harder to do so. Definitely not impossible, but a lot harder. The money people DO make from writing blogs is not so much the blogs themselves as it is selling products or services associated with the blog. IOW, the blog itself is secondary. There was even a discussion on here a few months back about it.

Here is one such article.