In October 2007, Brian Chesky and Joe Gebbia needed money for rent. A design conference was coming to San Francisco, and every hotel was booked solid. They set up three air mattresses in their loft, launched a simple website called "Air Bed and Breakfast," and rented the spaces for $80/night.
Their first three guests — Michael, Kat, and Amol — confirmed the core hypothesis: strangers would pay to sleep on air mattresses in someone else's home, and homeowners would let strangers into their space for money. Both sides of the marketplace showed up willingly.
The product they built to test this was deliberately minimal: a few pages on a self-hosted website, hand-photographed listings, email communication with guests, manual payment. There was no platform, no search, no reviews system. The founders personally handled everything.