August - 9:24 pm on Mar 3, 2013 (gmt 0)
did the epc change much? did the number of clicks change much?
Nope, that's the part that's really odd, and what makes me wonder about a revenue cap and/or throttling.
When we open the gates from 10% to 100% of traffic, the total number of page views and ads served stays consistent. The EPC and CPC remains virtually the same, as does page RPM.
Since the rotation is random, the sampling impression that Google receives ( spiders vs real human traffic, etc ) is the same whether they are getting 10% of 100% of the page impressions.