Slash my search is awesome, because they make money when people search through them, and as a reward, they pay you a fraction of the money they earn. They say it comes out to about 25 cents an hour, but my experience has been better than that. now, 25 cents an hour doesnt sound like much, but think of finding a quarter every hour, after a while, it adds up. also, if you get your friends to start using the program, they make just as much as you, but you make a percentage of what they make also. So if you get a group of friends together and you all do this, it could be quite lucrative, as the diagram shows.
To check it out, visit Slash My Search
The other, less effective one is Zotspot, but it does not offer as much, or as much money per friend reffered. other than that, they operate on basically the same principle. check it out at www.zotspot.com
