Your Domain Name is a powerful marketing tool. Promote your Domain Name on your business cards, letterheads and marketing material. Cypersquatters are people that register Domain Names and approach companies with the intent of making financial gain out of selling the registered Domain Name. Your domain name is portable. It is independent of your ISP, hence your web address and e-mail will remain constant wherever in the world you may venture.
Some engines are reluctant to list a site without a domain name.
Not sure if you have a true Domain Name or not - look at the following examples. If you fall into the sub-domain category you should register your true Domain Name immediately. Provide a solid perception of size, stability and professionalism for your company's presence on the web. Again there are several organisations that control each domain space. Com controls the .net.au space and various other bodies control the other au Domain Name spaces.