The domain name auction facilitates the buying and selling of currently registered domain names, enabling individuals to purchase a previously registered domain that suits their needs from an owner wishing to sell. A Drop registrar offers sales of expiring domains; but with a domain auction there is no need to wait until (and if) a current owner allows the registration to lapse before purchasing the domain you most want to own. Domain auction sites allow users to search multiple domain names that are listed for sale by owner, and to place bids on the names they want to purchase. As in any auction, the highest bidder wins. The more desirable a domain name, the higher the winning bid, and auction sites often provide links to escrow agents to facilitate the safe transfer of funds and domain properties between the auctioning parties.

A number of factors have contributed to the rise in popularity of the domain name auction. The personalization of the web resulted in domain names being purchased by more private individuals and businesses than originally anticipated; and as a result there was also a rise in speculation and domain name warehousing. Anticipating a growing need for a targeted top-level domain name, domainers began to purchase names with an eye towards selling them at a later time. The advancing field of Search Engine Optimization (SEO) has also increased the desire to own a domain name that accurately reflects the subject matter of the web site.

A domain auction website provides the technology through which users can list or purchase multiple domains easily and conveniently. Domain parking, once the most efficient method for advertising a domain for sale, allowed a domain owner to post the availability of the domain on a page, hoping someone who was interested in that name would surf through and see it listed for sale. With the development of the domain auction, multiple users can list multiple domains all in the same place, thereby exposing them to a greater number of potential buyers. Sites such as eBay have made using auctions very commonplace, and domain auction sites also require little to no technical knowledge to use.

In the past, if a domain name was already registered by another party, it was generally advisable to choose a different name. Whether current owners list domains for auction for a specified period of time or provide an instant purchase option, the domain auction has become an important tool in uniting buyers and sellers in the quest for the most beneficial domain name. However, this only accounts for an extremely small percentage of actual domain auctions. The vast majority of domain auctioning results from a practice known as "cybersquatting." This practice, already illegal in many jurisdictions, involves registering a domain name for the sole purchase of re-selling or auctioning it at a dramatically inflated price. Most domain auctions can be attributed to this practice. Many predatory buyers will even employ software to search for newly-expired domains and register them out from under the original owner before s/he can renew it. This practice is often used to extort large amounts of money from legitimate domain name holders who rely on their domain names to remain in business.