Users create a Facebook-type profile and build an eBay-style reputation via mutual feedback.
Payment goes to Airbnb rather than to the host, who isn't paid until the guest has checked in, thus reducing the risk of an unsatisfactory lodging.
Some destinations not listed, such as Bonaire and Tahiti.
This website sells discounted date-specific lift tickets for single or multiple days. It has grown from seven resorts when it launched in October 2006 to 120 resorts in the U.S. and Canada this season.
The average discount on lift tickets is 33% and sometimes as much as 80%.
Some resorts are not yet participating.