Not as much as you used to, banner ad clickthrough rates are about 1/4 where they were 4-5 years ago. John Chow did a good article about it and how few big names rely on it anymore.
If you have a blog that get 20 visits a day you will make pennies.If you have a site with 10,000 page views a day you will make pounds, but not a lot.Adsense is not a get rich scheme but it does give...