We all know that we shouldn't expect our adsense CPC to be as the one suggested by the google keyword tool CPC, since it's the average of what advertisers pay to be displayed on google's network itself. And generally they pay lower for the display network (adsense sites)
But how much lower we could expect? That's critical when researching new niches. I pulled 6 of my sites and estimated what % is the actual adsense CPC from the GKT approximate CPC.
(All of those has got few hundred clicks, on which i've taken the average CPC)