Google AdSense, currently, can not be placed into ATOM feeds using Blogger. The project is under development and is only available to chosen members at the moment. But with a little “hack,” you will be able to place adds onto the posts in your blog, but will not show up in the ATOM feed. By doing the following you will be adding an ad to the bottom of each post (post pages), and to the bottom of the first post if there are multiple posts on that page (archives & main page). The instructions are in a .txt file because the post would not appear properly with these codes on the page.
The ads should work properly and should appear as they do on this blog. If you need more help, have any questions, or want to fix something just make a comment!
The link to the txt file is broken.
Blogger now allows you to integrate Adsense into your blog without any hacks. You should find the option under the Template settings.