frankbomarito - 12:06 am on May 11, 2012 (gmt 0)
I advertise on adsense and the cpc rates I pay automatically drop if the ad is popular. (upwards of 1% click thrus)
I have my max set at $0.50 but usually pay less than a third of that.
I'm sure thats what happens when I show adssense ads on my sites too which would explain why the "hot" ads dont pay well for long.