At this week's TED conference in Vancouver, Airbnb cofounder Joe Gebbia revealed the email that launched the home-sharing juggernaut.
In 2007, Gebbia and cofounder Brian Chesky learned a design conference was coming to San Francisco, and all of the hotels were sold out. Gebbia pitched Chesky (his best friend and roommate) on renting out a space for these people to stay in.
The text: "brian, I thought of a way to make a few bucks - turning our place into "designers bed and breakfast" - offering young designers who come into town a place to crash during the 4 day event, complete with wireless internet, a small desk space, sleeping mat, and breakfast each morning. Ha!"
That idea ultimately spawned the Airbnb we know and use today.