Most professional website that base their income on ad selling will not rely on a Pay Per Click affiliate model, but will have an "Ad Sale Departement" that will sell most advertisment by a cost per Impression model (CPM, Flat Rate).
By professional websites I mean website that will have a team of people working on it that are depending on the ad revenue.
You are correct in saying that those kind of website are a extremly small subset compared to the many small website with a couple of google adsense banners, but are probably the website you read,consume and block the most.
If by professional websites you mean a few specific publishing websites which google has an CPM agreement with, then yes, those are a extremely small subset. News sites particularly are one large subgroup of that set.
But not all Professional websites is news sites. Nor is every professional website using the CPM model just because they got a team of people which are depending on the ad revenue. They commonly use the other form of compensation model which one can read in the above Wikipedia link.
CPM model is an rare/antique model outside publishing (news) sites. While looking around for statistics, I can't even find anyone that mention CPM alongside with PPC and PPS. PPC looks to be the dominant model, with PPS taking almost everything else. (https://strategyplanone.wordpress.com/2012/07/20/pay-per-cli...)
By professional websites I mean website that will have a team of people working on it that are depending on the ad revenue.
You are correct in saying that those kind of website are a extremly small subset compared to the many small website with a couple of google adsense banners, but are probably the website you read,consume and block the most.