I always looks at these with interest since they definitely show a trend, so what happened to me?
I started the year with 27.6% TabMob and ended with 36.6%, the quarters went like this:
Interestingly over the year tablets went from 17.4% to 21.0% whereas smartphones 7.1% to 15.2% however November alone was 17.0% and December 17.8%, that's just over a 250% increase.
All I use on my html5 responsive sites are two ads, a 320 x 100 at the top and a 300 x 250 at the bottom, nothing else, overall CTR on these sites is better than desktop with the 300 x 250 easily the higher earner but, most interestingly, over the last quarter an identical CPC!
Has anyone else a comparison?