When I am evaluating a domain name to buy in the aftermarket – either via auction or private acquisition, the number of TLDs (extensions) that are registered with that keyword or keyphrase is a critical metric for me. The more domain names that are registered in different extensions, the better and more valuable the domain name usually is.
It isn’t the number of registrations that makes the .com domain name valuable though. It is the fact that other entities have valued this keyword or phrase enough to spend money to secure different variations of the domain name. The more registrations typically signifies the more others would covet the opportunity to have the matching .com domain name, making a potential sale more likely.
There are a number of ways to find out how many TLDs are registered for a particular keyword or phrase. I have been using the DomainTools Search tool for this purpose for a number of years. There is a cost to using DomainTools, though. A free tool that many people use and I have found useful recently is ExpiredDomains.net. This tool allows users to sort by the number of registrations, so others who think this metric is important can identify domain names of value.
You probably noticed the asterisk in the title of the article. That was intentional. On some keywords and terms, you will find that one entity registered a whole swath of domain names with that term. Perhaps they were launching a product or service, and they bought out a whole bunch of domain names for defensive reasons. If that is the case, it could give the impression that there is more demand for the domain name than there actually is.
It is important to take a look at how the other extensions are being used. Not only does development on many different TLDs make the .com more valuable, but it can also make it more defensible. I think a UDRP panel would have a hard time ruling a domain name infringes on a trademark if there are 30 websites operated by different companies using different TLDs.
DotDB.com is a great tool for this.