Damn. That's an aweful lot of negative responses on a method that could easily be adapted to make quite a bit of money.
For example naysayers, would you have an issue if the op said:
"Our contest is sponsored by XYZ. In order to be eligible for the drawing, we need to confirm that you have joined XYZ as they are also our fulfillment company. That means they supply your video sex partner. So please complete your profile ASAP. We will be drawing the winner on XYZ date, and shooting the porn 6 weeks after that. Get set to get it wet my friend. Sign up NOW!"
So instead of direct compensation via paypal which is definitely problematic, you are essentially providing a false incentive for them to complete a profile signup for which the PORN company pays you. As I see it, that isn't a whole lot different than any of you working the gateways, and codeblockers methods. With enough volume, you could definitely make money in almost any adult program.