Hi,
The first 2
CPM banner ad networks listed here are very good and reputable companies that always pay me on time, every time.
You are allowed 1 of each ad format per page. I normally put 3 ads on each page (3 different ad formats). Each ad format earns me around $0.45 - $0.70 CPM on my
entertainment site giving me around $1.35 - $2.10 CPM (thats $1.35 - $2.10 for every 1000 pageviews).
Now these are just banner ads with no popunders or anything else with them. The CPM earnings per banner ad from these 2 networks are higher than most of the other CPM Ad Networks.
I don't quite get a 100% ad fill rate so what I do, I chain both of the networks together so that when one network produces a default it will show the other networks ads instead of the actual default. Doing this will mean you will earn even more from your ad space.
If you want to earn even more then you can also use their popunders which you can set up so 1 popunder gets shown per unique visitor. This will make it not annoy them so much. If you use popunders aswell then when I use to use them I was earning around $3 - $6 CPM extra and you can also chain these aswell.
If you don't get accepted into these 2 networks, then there are a few CPM ad networks listed further down in the listings that you are more likely to get accepted into, but pay a little less.
Good luck with all this banner ads stuff and hope you do well.