Skill: Basic
Income: Passive, Active
For: Publisher, email marketer
I use this method and for every site I visit(min. 15-40 sec.), I could in return send a visitor to one of my site. But my time is precious and I paid $5.95(passive) thus I was able to send 1000 real visitors anywhere I wanted. Paying is optional and you could do it for free(active).
It's not the fastest way to make a lot of money but they have an affiliate program that pay you $0.10 per referral. The referrer must visit 100 sites. It's done using a frame. You can cash out when you have $3.00.
If you have a site, you could make your own landing page just for them. You should make it simple so that the person will want to stay longer than the minimum time required or give the person a way to open another window for later.
Depending on your country of origin, $3.00 may represent a great deal of money. Many forget that not all people earn $20/hour or more. Then again, the cost of leaving is not the same.
Keywords: Active, Basic, No site, Passive, Publisher