ISAs are a good idea, but there's no way you can start a <i>hyper-profitable</i> business around it. It's literally a ponzi scheme under those circumstances as the total amount of students "pending" will always exceed those who are paying out as the mandate is to grow.<p>The potential solutions are three fold:<p>1. Limit growth of students - impossible if your organization received venture capital.<p>2. Reduce the cost to educate - Unfortunately if you make education a commodity, ironically it will be replicated, leading to alternatives, ultimately leading to (1).<p>3. Guarantee the loans somehow<p>I think the only type of organization that could pull it off is one that doesn't mind waiting a long time to do it sustainably. Probably a not-for-profit. Alternatively, you could sustain it by doing it at a loss, e.g. you have some other organization to ensure (3).