Google Opens Up Adsense for RSS

Google has opened up its  contextual Adsense ads for RSS feeds to any web site owner. There's one catch, however. You must have more than 100 feed subscribers to sign up. Most people don't have any idea how many people are pulling their feeds - unless they use a service like Feedburner. Although 100 readers is certainly a low bar, this gets me wondering if Google is perhaps going to count a feed's RSS subscribers as part of some broader master plan for feed monitoring or perhaps searching. Is some roll up with newly-acquired Urchin in the cards?