I have no idea how to "exploit" them, but I'm using TrafficSwarm at the moment, and the hits are real and 1 to 1 on the ratio, basically. I've tracked them through viralurl, and can see where exactly the hits are coming from, and it shows every click through from TrafficSwarm so I know they're legit.
That's the only one I've signed up with, as I found out, like the others have said, that you may get some traffic, but it's not buying traffic. I do have netaudioads on a couple of the sites, so I do get something (when the bloody ads are working!) for each "visit".
I can see where using a CPA (I've got to sign up for those!!) would have a better chance of bringing in some money. I tried it with a CJ program, but got paranoid about the lack of impressions compared to clicks and stopped that for now.