How many CPM ads/per page?

Hi, how many CPM ad's i can place to 1 page?

Idea is something similar to 9gag.com(content, content, ad, content, content, content, ad and so on).

Anyone?

There isn't a universal max number, it depends on which network are you working with.

basically it really depands - Adsens would allow up to 3/4 ads (5 if you use ADX ) but i used to work with this guy who had an A:B tester for Adsense and sometimes 3 ads made a better rev per page than 4/5 ads so you need to split test and see what works best for you.
other performance networks will probably not limit the number of ads but you do want to keep your site with a reasonable amount of ads VS content.