I have asked that same one in other forums and have gotten the same answer.
Nobody wants to answer it.
I have been trying to make money online for years and the best sucess that I've had was with Overstock.com. I came home from vacation two years ago and found two checks of over $300.00 dollars each. I did not advertise that much at the time. Since then I've worked their site very hard and have not made a penny.
I can't figure it out.