I have many sites with ok traffic. Each is nothing to write home about but I am very diversified and I have alot of websites. You can guess that cpm ads do not pay well for me and I want to block them. Im looking at my most popular pages and I notice that many of them have only 1 ad showing in a 4 ad block. Others have 2 ads. My initial thought was that the one ad in the 4 ad blocks were cpm but now i'm wondering if maybe they are just optimised ads by google. Meaning google has figured that showing one ad is getting me more clicks.
How do you tell an optimised ad block appart from a CPM ad?