Plenty of other industries have gone through regulatory issues on their way to becoming accepted: when eBay was gaining ground, it faced fierce resistance from traditional retailers; one of its opponents tried to pass a law requiring that users have an auctioneer’s license to sell on the platform. Payment start-ups from PayPal to Square to Stripe had to prove their legitimacy to regulators who were horrified at the idea of exchanging money online. “Success almost always results in legitimacy,” says Airbnb board member Jeff Jordan.

