Through income share agreements (ISA), students pay for their education as a percentage of their post-grad income rather than a flat up-front charge or a conventional loan where they are on the hook for a fixed monthly payment regardless of what they’re earning. I sat down with @KJMumford of @LifeAtPurdue and @ethanpollack of @jfftweets to learn more about what they’ve learned from studying Purdue’s “Back a Boiler” ISA program—and what those lessons might mean for making ISAs a bigger part of the way students pay for college.