Airbnb started in 2008 with a simple pitch, rent spare floor space when hotels were full. That origin mattered less than the system it built next. Profiles, messaging, secure payments, and public ...

Brian Chesky, a former hockey player and industrial design student, is now worth $9.1 billion. Chesky started Airbnb after renting out his apartment to conference-goers who couldn't find a hotel. See ...