What is the advantage of creating an internet domain for my small business?

Creating an internet domain allows you to show your brand name in one more instance. For example, if your company name is "My Company, Inc.", you might register the internet domain names mycompany.com, mycompanyinc.com, my-company.com, and my-company-inc.com. Each of these names can be configured to point to the same web site and e-mail server. The goals of internet domain names are to be sufficiently distinct and memorable that your customers can find your business and not be confused by competitors.

There are multiple top level domains. In the USA, .com has typically been used for businesses and .org has been used for non-profit organizations. The variety of top level domains has expanded in recent years so domain name registration services now offer a large variety of top level domains. While registering some additional domain names might be useful, it also increases the ongoing costs.