Startup Idea : Couchsurfing for Facebook

As we know there are many websites like couchsurfing or airbnb.com where people offer their places to other people to stay. but we should accept that not everyone knows about these web sites and sometimes it is too complicate to control several accounts.What if we create a system and then suggest to Facebook where people can offer their accommodation to friends or friends of friends. People can have a little button on their profile where they can indicate that they can offer their place for free or certain amount of money to other people. With this way person can earn get extra money and other people can be sure that they are staying in a right place. This will create new friendship relations and also increase a little bit in their budget.What do you think? Who supports this idea?