Sgt_Kickaxe - 12:57 am on May 10, 2012 (gmt 0)
Either your CTR is down OR, CPC [AdSense term] is down OR both which is it?
Without giving specifics: The number of ads requested increased as you'd expect from adding another website and creating new units, as did the total number of clicks. CPC dropped as did ad request CTR ratio and, ultimately, RPM is down a good deal resulting in earnings nearly cut in half.
So, number of clicks increased but the number of ads requested increased more which apparently sent epc into a tailspin. To me this reaffirms that you need to parse lower paying units from your overall account in order to maintain a higher payout for everything else. It's somewhat counter-intuitive that more clicks would lead to less revenue but that's exactly what happened and it all started at the exact same time I included this site into my account.
Solution(if there is one) is to remove the units from this site and recycle them through my other sites to wipe their memory so to speak. I wish I could just delete them but that's not an option.