... your getting the income every month, but then somebody leaves? Do you stop and start payments, or do people keep paying months on end with no update?
1 off payments work because you pay for what you get, and bonuses come afterwards. If you're paying 5 bucks a month, and development ceases, what happens? Do they still pay their 5 bucks to play. What about late-comers, who wait till patch 5, they then spend 5 bucks to get the game, don't want any more updates so splash, some people pay 100's, while this guy pays 5 and gets the same...