I agree that one of the most important things is to have targeted visitors i.e. that ads should be related to your niche.

i am working with neverblue, which has lots of CPA offers, but hard to get in, you must have some experiance already in selling

Affiliate marketing basically can be described as using one website to drive traffic to other.
it is a type of online marketing.it is generally underestimated by advertisers.
While search engines, e-mail, and website syndication apply much attention of online retailers, affiliate marketing carries a much lower profile.

As far as I know very popular are affiliate programs of the software companies. They give huge commissions if you join their programs. My suggestion to you is to try to be affiliate of e-commerce solution. This will bring you a lot of money.