In the days before AirBnB I rented an apartment in Paris for a week and had to wire half the money up front (in EUR, from the USA) and bring the other half in cash on arrival. The apartment was awesome, the host even better and I had no regrets. But it was a hassle, a bit risky, and certainly not something most of my friends and family would have been willing to do.

Getting in the middle of the money may not seem like much of an innovation but from my own experience it was probably one of the more complicated aspects of their platform. Dealing with currencies, escrow, risk management, settlement, chargebacks, etc. is a major undertaking. But it’s what made the model accessible to a lot more hosts and guests.