AdWords Relevancy & AdSense Revenue Take a Hit

Last night, I received an email from Peter Da Vanzo, you know the guy who started that new cool directory named Rubber Stamped. Well in a blog entry he named First Rule of Adsense he mentions a thread over at WebmasterWorld about people noticing two things:

(1) Drop in AdSense Revenue (2) Drop in AdWords Relevancy

Are they related, probably.

The thread gets really interesting, tons of those fun theories.