You registered "alternate root" domains. There have been many companies trying to sell these for years. None have really succeeded to any extent. New.net was probably the closest to having some success, although short lived. These companies basically are not really the Internet, but a private network using the Internet data pipeline. Standard browsers and routers don't see the sites unless you use the "alternate root" servers for DNS, browser plugins, special browsers, ISP's with agreements to carry the root DNS, or in the case of new.net they also were third and fourth level subdomains off of new.net.
As you've already been told, they are pretty much worthless. Since they don't resolve normally, no one would build a commercial site on them, meaning there is no real secondary market, and not much of a first level market.