CouchSurfing International Inc. is a company based in San Francisco that provides hospitality social networking. Travellers using the service stay at a host's house, where they sleep on a couch (sofa) or a mattress on the floor. The service is intended to be free of charge; the host does not ask for money from the guest. CouchSurfing is intended to be a cultural exchange program, where the host shows the visitor around their town or local place, and the guest delivers his or her own country's culture.