It has a more professional connotation for your business and your web site's presence.
If wish to change your Internet Service Provider, you can move without altering your stationery or creating dead links.
You will do better on search engines. Most search engines will not consider your web site to be a professional business unless you have your own domain name. Many sites that are hosted by free services are not indexed by some search engines.
4. If you have a keyword in your domain name, you will rank higher on most search engines.
If you use your business name, your clients and customers can easily find your web site by remembering your name. With BNS it is even easier since visitors do not have to type the ``www." first. You will be found both with or without ``www." before your domain name.