Been using adsense for what seems like forever on numerous sites and have noticed a strange trend. About 10-14 days ago the partner and I were bragging about how well we were doing on adsense because the revenue per click was averaging over all our sites about 45 cents for the year. This week we are seeing an average of barely 9 cents - across all of our sites. I've never seen such a long sustained period of time of 3 cent clicks. Tell me I am paranoid... Maybe the lesson is never brag because the google gods will hear you!
The low clicks could be something that everyone seems to go through, or oit could be that your account has been smartpriced because of low conversion.