With the ever growing popularity of the Internet, more and more companies are getting online with domain names and a web site. It's not uncommon for a new company to find that the domain name they wanted has already been registered. The first thing the new comer will do is check the availability of the .NET version. Most of the time your domain name is your company name. If it's not your company name, it's probably just as important.
Most companies guard their company name and logos with trade marks.
You can guard your .NET domain by registering it. Many companies have already done that. Many other companies are in disputes over their .NET domains. Other companies have found that having a .NET allows them more flexibility. Some companies address all internal corporate traffic through the .NET domain name.