Estiva

Adsense and traffic exchangers are not a good combination as adsense doesn't pay for that type of fake traffic. So only way to use traffic exchangers is by asking for referral links(i mean inputing it while you're earning 1:1 traffic from them).

kiddoman

You can try to find some friendly sites with link exchange and review post.

investor999

Ad sense will not allow you to use those sites where you have their code in them and often your account will be banned but there are other options which just give payment for valid clicks will have no problem so you can use any of them like bidvertiser,chitika,adclickmedia and others but they can not be compared with ad sense because they do not pay for impressions, you can use other sites which pay for impressions.But yes I do admit Google is the widest one having a major share because of their prominence and mastery on the subject.