I get that. But from the perspective of a traveler, for any given well traveled city you are going to find an equivalent host with equivalent accommodations at both sites. I wonder if it would have been wiser to start Airbnb.com as the web 2.0 version of couchsurfing, and then go freemium. Something couchsurfing wouldn't do.

It's a different target demographic. In a trip to DC recently, we got a private room on AirBnB and saved roughly $25 pr. night ($75 vs. $100) over the hotel we'd otherwise have used, and we got a better experience for it.

We didn't feel any obligation to hang out with the host, bring gifts or stay in touch, or to accommodate our host or anyone else at our home -- which made things a lot easier.

I think it's more correct to think of AirBnB as cheap hotel, not premium couchsurfing.

I agree. As a budget traveler, I'd love a service like AirBnB, but all of the listings are too pricey. If they targeted the frugal adventurers, I could see a community of such people developing around the site, and all travelers would use AirBnB, not just the richer ones.

While this could be painful in the short-term, it would help them achieve the ubiquity that they seem to want.