Domain buy-sale or reselling is becoming more and more popular. Buying & Selling domains is a good way to make money if you know what your doing. Remember to research the potential end user for your domain and if there is a market for it. There are numerous domain listing/auction sites on the web like AfterNic.

Webmasters who are registering a lot of domain names for themselves or their company can benefit by reselling domain names themselves. As a reseller they can buy domain names for discounted prices and make money off the registrations of others.

The two largest domain name reselling companies are Enom & WildWestDomains. WildWestDomains is run by the same people who run GoDaddy.