Pay per click

Many people search for Pay Per Click. But first what's Pay Per Click.
Pay per click is a program that will pay for your site (or to you) every time you get a click on your site.
The best Pay Per Click program is Adsense (for earning sure). And if you are the advertiser then you would use Adwords.
Those are the most famous, simply because they are supported by Google.
If you are the advertiser then you may try Stumble Upon. Stumble Upon has lower costs (obly 0.05$ for visitors).
Stumble Upon has a lot of visitors that searches for sites and this is also a great program.
Adwords may be costing, but if you choose affiliate this will be better.
By becoming an affiliate, you'll pay only when visitors buy something from the site.