Have you tried infolinks?

[nomad]

Infolinks is CPM and CPC based ad networks, it is mainly text advertising network where they place ads within the hypelinked keywords on your site. They also offer banner ads for sites that have a lot of North American traffic.

 

[Ratine]

I think this is one of the main website monetization being used by webmasters. I have never tried that one out.