That's an interesting exercise, but in reality I wouldn't expect enough of my friends to pay to stay on. There would be a mass drop in the number of users, significantly devaluing my membership. So if that were to happen, I wouldn't pay anything. However, if they said "We're now at even cash flow, but have amassed a lot of debt! We don't intend to take this towards profitability, but please help us stay afloat." I might donate 10 or 15 bucks. Not that I expect that to happen either :-)