I have the same problem... from end of May I see stady dropping of adsense CTR on my websites.. It has dropped for 2.22% by now.. And I didn't do nothing.. I guess it has something to do with msn shifting their algorithem a little... or is just this football euphoria and nobody is clicking on ads
I also noticed a small drop in CTR after 3rd June. My earnings went down by 1/3 after that date. Maybe its a bug in Adsense or maybe the 7 billion page man took all the good ads i was being served ?
good one You remembered me I got one specific email from adsense team on 24. May. Apparently a lot of mother earth looking adsense ads were changed to borderless open air. I guess this also means CTR went up for some websites.. and this means more ads served on "mother earth" websites.... Do you think it is possible that CTR went down because of this change?