Requires going through the FeedBurner platform to insert ads into your feed — that means changing the feed URL you give your readers, transferring your existing readership (a simple redirect) and trusting an outside service with the entire future of your blog. Basically, it’s the same as if the only way to have AdSense on your blog was to syndicate your contents on a Blogger page, and having to give that address to all your readers. That’s not why I bought a domain name (or fifteen).
I never understood why so many blogs decided to rely on FeedBurner for some dubious additional functionality (I’ve never seen anyone attribute any reliability to the subscriber counts), even if the service is now managed by Google. And the possibility of inserting ads on my feeds won’t change my mind; it’s not like anyone clicks on ads in their aggregators anyway.
Still, the principle of the thing is lame; there’s got to be a way to do things more openly, with some kind of API.