Domains are nonmaterial goods. When sold, the only transaction taking place is transfer of domain rights from one user to another. Barring any form of copyright or trademark violation, virtually any domain name can be bought or sold. Generic domain names, such as car.com or computer.com, are not legally protected and can therefore theoretically be reserved by anyone.
Prospective buyers can contact domain holders directly in cases where the desired domain is no longer available. Most registries openly publish the names and contact data of domain holders. Once this information is gained, buyers can get in touch with domain holders and make them an offer for the name. Sales are also known to occur even when the original domain owner may necessarily have never had any prior commercial ambitions