not crazy
1. go look at Hyatt's financials. Back in 2010 fiscal year Hyatt only generated $66M of net income. Why? Because hotels generally have high operating leverage (i.e. high fixed costs) and low margins, so small downturns in demand for rooms can have a large impact on profits. And frankly, AirBnB is helping depress demand for hotel rooms.
2. now think about AirBnB's business. They take 3% of every booking and they probably have low incremental costs (just additional server capacity).
The article below says they booked 12-15M in rooms in 2012. At an average of $100/room night (probably conservative) .. that's ~$1B in bookings with $30M going to AirBnB.
http://www.businessinsider.com/airbnb-billion-revenues-2013-...
We know AirBnB has grown rapidly ... and in the article they say they think they can serve 100 million in bookings per year ... which would equate to revenue of $300M. You can start to see how AirBnB could in fact produce as much profit as Hyatt without owning hundreds of properties.
Finally, don't bet against companies that combine economies of scale and customer captivity. I'd say that AirBnB has customer captivity because of the difficultly of establishing 'trust/credibility'. Once a user has established that credibility at one site I think they're fairly captive.
Anyway, time will tell. It's going to be fascinating to watch.
