Your choice of a top-level domain (TLD) can make a considerable difference to how memorable your site address is, and hence, how much traffic you can expect. .com is, of course, the most popular and recognisable TLD, but its generic nature and enduring popularity has led to difficulty in obtaining addresses which use it. If you have your heart set on a .com address, but find that your chosen Domain Name is already taken, you could change your name to something that hasn’t been taken, perhaps by adding hyphens or prefixes, or abbreviating a portion of the name of your site. However, this may involve compromising on how memorable your site name is.

You could choose a .net address instead, especially if your site is internet-related. .org is the TLD for non-profit organisations. Although there are no longer restrictions on who can register a .org domain, many users will expect that a .org address will be that of an organisation. The .info domain is open for anyone to register.

Country-code top-level domains, or ccTLDs, can be extremely useful if you wish to target your business or organisation at a regional market. The .co.uk TLD is an example of this; sites which end with this TLD clearly trade in the UK. A popular choice is to register ccTLD equivalents of a .com address, in order to have sister sites for different regions. This can be useful if you have versions of your site in different languages, or if your pricing varies depending on the country you are trading in.

If your site is for business use, you might consider the .biz TLD, which offers a higher level of security because enhanced authentication is required to register. .biz is strictly for businesses.

Finally, if your website is purely for personal use, you might want to register a .name address. Unlike most other TLDs, the domain you will register is a third- (as opposed to a second-) level domain; for example, the "jane" in "jane.smith.name" is the domain that you would register. Mail forwarding is also offered by the .name registry; you can have jane@smith.name, for example, which will forward to an email address of your choice. .name domains are highly memorable for family, friends and colleagues, and may in future become what the .name website calls a "unified digital identity", being a secure online repository for personal information. .name domains can also be used for fictional characters, so they have become popular as addresses for fan sites.