Adsense for feeds allow ads to show with your feeds. You can choose if you want them to appear at the top or the bottom of your posts. They're always relevant to your topics and appear in small windows (just like on your blog). You earn money when visitors click on or view these ads. A feed, simply put, is a plugin that offers your reader a way to get regular updates every time you publish something new.
You have
enabled targeted Google Adsense on your blog and you've burned your feeds. If you haven't targeted your Google adsense on your site you may be losing lots of money. Go to the link and you will see a very simple tutorial of how to make your Google adsense work better for you.
On the other hand, if you want to burn a feed here's a super, step-by-step article showing you how to
get a feedburner account for your blog.
After
publishing Google adsense on your site, you may think that your Adsense for feeds are automatically enabled, but this is not so. However, there is great news! You can enable adsense for feeds with just a few clicks. Please note that you need to have a feedburner account before you set up adsense for feeds. The above, linked article will help.