1) In 2007, two RISD alumni, Joe Gebbia and Brian Chesky, living in San Francisco were struggling to pay rent and had no place for visiting professionals to stay.
2) They came up with the idea to rent out air mattresses in their apartment, creating the first version of Airbnb. They hosted their first guests, raising $80.
3) After positive feedback and more bookings, they refined their website and business model, eventually raising millions in funding from Y Combinator and other investors. Airbnb has since grown tremendously in users and valuation.