I usually get 0.15-0.2 for click... before 2 weeks i got smart pricing (0.03-0.05 per click!) so i remove the ads and today after 2 weeks i put the ads back and earn only 8 cent per click! (my blog running for 4 months and the problems start only in july) My earnings now only $30 day! before i had $100 earnings or more! 10K uv daily with 3%-4% CTR!
Well I guess google has decided thats all your traffic is worth. Maybe add infolinks as well they have some decent payouts and it works well along with adsense.
you must think about high paying keyword and traffic targeted. try to get huge traffic from US or U.k
Did your ad impression and ecpm dropped? If they didn't, then it should be because Big G need a while before releasing higher cpc ad to you.
Check if the quality of your traffic changed. For example you might have received mostly US visitors first, than google decided to lower your ranking and now you only getting India/China only, thus lower CPC.
99% of my visits are from israel.. only israel. There is no change in my niche, visitors or CTR. I already block low paying ads and nothing changed. Maybe is the site?
Whenever I spot a sudden downturn in income/CTR, I check in my adsense account and see what ads are displaying... I usually can immediately find a bunch that are nothing to do with my site whatsoever. It happened last week and when I looked there was a bunch of annoying, childlike, adverts for email addresses. Killed those off and up went the earnings and CTR back to their normal levels. I've only had to do this about 3x in two years though, it's not a regular thing.
It is the kind of ads that are being displayed on your website that have resulted in the lower pricing. Recently I have noticed that google determines my interest from the kind of websites I am visiting as opposed to the content of website I am visiting. This is weird. Last few days, I was checking out some shopping websites, then went on the internet marketing forums. Google Ads were being displayed as shopping website ads in IM forums.