Recruiting spare gamers' GPUs is one thing - those people bought the GPU anyway, so as long as you pay more than they pay for power, they're happy - but I imagine that's a relatively small pool of GPUs.
At some point, you'll run out of those people, so I guess what I'm asking is whether the price you charge now is high enough that investors could profitably build and run their own "mining" hardware , while you still get enough of a cut to run your service.
