Just read an outstanding article about how to make money on a blog. This guys stats are just mind-blowing. $1000/day! Personally, it's an outstanding day if I break $1, and the average is sitting around 22 cents/day.
As justification for my ads, just think: At some point (well in the future) I'll finally manage to make $100, then I'll get a nice check from Google, and do something fun with it. Then I'll blog about it, and all of my fine readers can revel in my fun-having, and it'll be like you earned $100 too!