While you cannot buy a domain name, you can maintain your lease as long as your registrar exists. The first step is, of course, making the initial payment to lease your chosen domain name. Registration typically lasts for a year, so you'll need to keep the date of your initial registration in mind.

Each domain name has its own registration and expiration date. Most domain names can be registered for a period from 1 to 10 years. They can be renewed, if necessary, while they are still active or reactivated after their expiration date.

But popular domain names can be expensive because of a secondary market of resellers who buy and sell domain names for profit. The domain name carinsurance.com, for example, sold for a record $49.7 million in 2010; sex.com has sold twice, once for $14 million in 2005 and again for $13 million in 2010.

Whether or not a premium domain name is worth the cost comes down to how much it will benefit your site. If you want to make money and attract as much traffic as possible, the right name can be worth the investment. However, for most sites, it's easy to find a regular domain name that works just as well.

You usually must renew your domain name once a year to keep it active. The company that issued your domain name should remind you to do that before your domain name expires. The consequences to letting a domain name expire could be significant depending on how your business uses its website.