So, with all this talk about the new QS coming to the content network, I noticed a sudden jump in CPM ads, starting November 9th, and I recommend to check your stats as well.

Where before the CPM ads were generating on average below 0.1% of total single ad impressions, they now represent >1% of single ad impressions. Still not enough to take action IMO, but an almost 20x increase is telling me that somebody somewhere is sweating heavily under the new QS algo. Which makes me :-)