People who have air-matresses list themselves on the site and charge guests between $10 and $200-ish for the night (and the breakfast).
Is this going to replace hotels or even hostels? Not likely, but if you're super strapped for cash and especially trusting of strangers, it probably works as a much nicer alternative to the Craigslist ads and corresponding Craigslist creepsters. At least AirBed&Breakfast requires pictures of the apartment hosts.
What do you think? Would you forgo a hotel for an air mattress? Ever? Tell us what you think.