Your domain name, whether you like it or not, is your online identity. A lot of effort is ordinarily put into choosing an effective domain, whether it is keyword-heavy, or the same as your storefront name. Less attention is paid to the possibility of utilizing different top-level domains, simply because ‘dot-com’s are traditionally the most popular. But it can pay to try to take advantage of a different top level domain, depending on your business type.
Top level domains (TLDs) are the part of a web address that comes after the domain name. You can find a full list of available domains at IANA.org, whee they have a country code list and a generic tld list. Some of the more famous ones are listed below.
Commercial: Open to any registrant.
Business: Must be commercial.
Information: Open to any registrant.
Companies: Open only to advertise jobs for own company.
Network: Open to any registrant.
Organization: Open to any registrant.
Profession: Open for doctors, attorneys, and cpas only.
Federated States of Micronesia: Common radio broadcaster tld.
Laos: Common Los Angeles tld.
Tuvalu: Common television broadcaster tld.
United States: Open to any USA-centered registrant.
The most important of these is the .com tld. Even if you decide to go with a different tld for marketing purposes, you must keep the .com tld as a 301 redirect to your main site; otherwise, you run the risk of a competitor claiming the .com version of your business name and profiting off your marketing.
That said, using a different top level domain can sometimes reap large dividends. One popular news blog uses a .tk tld, and advertises their site with "tk" phrases to push the unusual domain on blog readers. Having an unusual top level domain can boost your brand by making it stand out; and the drawback of it becoming less memorizable due it not being a .com is negated so long as you also register the .com version and have it 301 redirect to your actual tld.
If your business caters to a local market, having a local tld can be very useful. If you’re expanding into a new market and want to register the appropriate domain, make sure to do research first. Although .gb is the official tld for Great Britain, most companies there use .co.uk addresses. Also, former Soviet Union countries do not regularly use their own country codes; .su tlds are still very popular there.
Be careful not to put duplicate content on each of your domains. Always use 301 redrects to your main page and keep all your content there; otherwise, search engines may penalize you for serving duplicate content. But remember that there are no penalties for using less popular domains by itself, and it pays to be creative with anything that you market.
That said, you do have to be careful about a few items. Though it is rare, occasionally overzealous corporate spam blockers will deny email that gives links to a .biz name. This never occurs on spam blockers that you can purchase online, since blocking all .biz content is going overboard, but every once in a while a system admin will think it is a good idea and block all such e-mails from getting through their server. Also, sometimes the less often used tlds carry a connotation of nonprofessionalism; .my may look interesting due to it sporting a two-letter word (e.g., http://oh.my), but if your business has such a tld and it isn’t obvious why you chose it, then it could hurt your image.
If you do decide to leave the comfort of the .com arena and try out an alternate tld, make sure to market the name aggressively. Take advantage of your unusual domain name, because it is something that your company will sport that others won’t. Emphasize it, perhaps by using wordplay, or making it a different color in the logo. The point is to make the alternate tld work for you. After all, if choosing an alternate tld doesn’t help your brand, then you shouldn’t use it in the first place.