Anyone know how Adsense and Yahoo calculates how much to give to the publisher based on the cpm the advertiser is paying. Im having trouble figuring it out? Any help would be greatly appreciated.

I don't think they make those figures public. Keeps up guessing and working hard to optimize. Clever tactic really.

Neither Google or Yahoo publicize the split.

It would appear not to be a simple percentage, but a complex calculation dependant on a few factors.