The thing you miss here is... what do paysite owners get out of this? MORE bandwidth bills when your members are logging into their sites and downloading everything they have in that few hours or a day or whatever you mention? Once they have done this, they don't need to stick around. Who covers THAT loss? You? Nahh, the paysite owners do.
I tried this a few years back with someone, and I can tell you, it wasn't productive for anyone but the surfer..... you haven't seen nothing until you see a surfer going after that download button to get all the free porn he can get. It's like throwing money in the streets and expecting people to NOT pick it up. lol
Why not find sites with free to join offers and have them signup on those? Free is Free, right? And those sites are out there, all over the place.