OK I have a few small / new websites and I've seen adsense earnings jump around as there are various advertisers bidding various amounts. Now, one of the websites was pulling in clicks worth .60-$1 - steady for a few weeks. Its PR2, its a high competition niche, and although it doesn't have much traffic yet it was worth a few bucks a day. Then, after the following changes, every click is now worth 1 penny: -Verified in Google webmaster tools -Set up adsense channel for just that site's ads -Started getting more Google SE traffic I don't know why any of these would cause the CPC to drop so dramatically... I don't know anything else that changed over the time-frame. I get a few non-US visitors (maybe 10%?) so I guess its possible that they are the only ones clicking the ads... What other factors could contribute to such a radical drop in cost per click? Thanks in advance for any advice.