Now that Google Referral will be totally pull out in the market by Google, another product is being tested by the company right now. Adsense for feeds is now in beta publishers will be given another income stream from Adsense.
Adsense for feed will be using the technology by Feedburner, Google wholly owned subsidiary, I just discover just now when i logged into my account. Though it uses Feedburner, you cannot automatically used the features if you will be using the old site. Google now integrate feedburner in Google Accounts, which means you can log in to it using your Gmail account.
The problem for now is that you cannot used your old feeds, you have to request for Google to migrate your old Feedburner feeds to new Google Feedburner in Google accounts. If you will successfully done the migrations of your feeds then additional income is at hand. This new product product from Google gives advantage to publishers who have thousands of subscribers under his/her site. If you have minimal subsribers it follows you will gonna have a minimal income from Adsense for feeds.
You can check more information about this product in your Adsense dashboard.