One user has described AirBed and Breakfast as Craigslist meets hotels.com- but a lot less creepy.
Based on what I have seen of the site and its services, this seems to hit the nail on the head. The site allows people who are attending events- from the Democratic National Convention to the South by Southwest Music Festival- to find otherwise sold-out lodging. They do this by connecting individuals that are seeking a room with people that live near the event and can offer a place to stay. In the end, the homeowners garner a little extra income, and the visitors save money on lodging (and receive breakfast).
Airbedandbreakfast.com In Their Own Words
“AirBed & Breakfast is the fun way to share housing, save money, and connect with others at an event. Use it for conferences, conventions, festivals, concerts, sporting events, or any other event where people are attending from out of town.”
Why Airbedandbreakfast.com It Might Be A Killer
Beyond the fact that AirBed and Breakfast allows visitors to save money and homeowners to receive extra cash, AirBed and Breakfast offers other innovative advantages to both sides. Visitors do not have to stress about finding an over-priced hotel room and can meet and socialize with like-minded individuals, and homeowners can receive extra money without the permanence of opening a bed and breakfast. All in all, AirBed and Breakfast is a win-win solution.
Some Questions About Airbedandbreakfast.com
Could there be potential legal problems? How are payments set up? 
