Memorable domain names have great value. Among the domain names that are most easily remembered are situations where the name and extension match, such as com.com or win.win. These are called domain name twins. In this blog post I take a look at domain name twins in use, those that have sold, as well as a selection of domain twins currently listed for sale. So What Is a Domain Name Twin? I am not sure that there is a formal definition, but here I use the term domain name twin for domain names with identical terms on both sides of the dot. I use the short form domain twins and domain name twins identically. The number of possible domain twins would be at most equal to the number of Top Level Domains (TLDs). However, restrictions on some country code domain names preclude two-character names, so the actual number of available domain name twins is fewer. Also, some possible domain name twins are reserved by registries and unavailable. Domain Twins in Use The number of domain name twins in active use, other than as for-sale landers or parking, is not large. Here are some of the ones I discovered. blog.blog This redirects to a page for starting a WordPress blog. win.win This is the site for the Twins peer-to-peer digital currency exchange. ch.ch This domain name is actively used in a website with a variety of services by the Swiss government. com.com This would arguably be the most valuable domain name twin possible. It is currently used for monetized links. am.am This is the main website for a law firm with the initials AM. me.me This is a site where you can purchase meme-related items. This domain name twin is also a domain hack. be.be This short country code domain twin redirects to the Trimiday site, a P2B (person-to-business) site. The use is consistent with the Trimiday Me2B branding as a marketplace for individuals to provide insights, reviews and feedback to brands. gg.gg I expected possibly a gaming site for this domain name, but instead it is used for an URL shortener site. The domain twin to.to is also used as an URL shortener. net.net This website is active and makes the claim “the first and the best domain name on the Internet!.” However, the official creation date for net.net is October 22, 1994. That is definitely old, but not nearly as old as symbolics.com that was registered March 14, 1985. If the meaning was first web page, that is generally agreed to be a page set up at the scientific institution CERN by Tim Berners-Lee on Aug 6, 1991. In any case, net.net is a fantastic domain twin that has great value. world.world This is in use for a fairly new site that has the aim of “shifting the world (as we know it today) into a world of joyful potentiality.” The author of the site asks readers to follow his journey following a bipolar diagnosis. homes.homes This is used by the homes.com site, a homes related service that has roots all the way back to Homes & Land Magazine in 1973. fit.fit This fitness site has nice graphics, but the main role of the site was not clear to me. They do highlight the domain name twin nature of their site. one.one This domain name redirects to One.com, a major web services provider. live.live This is in early development as a site with recommendations and monetized links. xyz.xyz This is used by the registry to promote the .xyz extension. Also art.art has an attractive and informative website run by the .art registry. Interestingly, as part of that website they have a section on the ART Digital Twin project. This is not related to the idea of domain name twins, but rather it is an art identification and authentication protocol. sucks.sucks Unhappy about the .sucks extension? Why not tell them so at this domain twin site that redirects to dotsucks.sucks. Did you know that one domain name twin goes to a registrar used by many NamePros members? I didn’t, but in my domain twin sleuthing I discovered that love.love takes you to a Porkbun page that reminds you that “.love is all you need.” By the way the domain name spread.love also takes you to Porkbun. Domain Twin Sales At least as recorded in the NameBio database, I could not find many sales of domain name twins. Here are a few that I found. net.net sold for $100,000 in a 2004 private sale. live.live sold for $25,000 in 2016 on Rightside. top.top sold for $16,071 in 2015 on eName. horse.horse sold for $2000 at Sedo in 2016. UPDATE: See a complete list of domain twin sales at NameBio at this link below provided by @Michael. Domain Twins for Sale It would appear that a number of the twin domain names listed for sale currently are in a relatively small number of domain investor hands. For example, one investor has the following domain twins: cricket.cricket, email.email, fitness.fitness, group.group, horse.horse, link.link, work.work and others. Another site with multiple domain twins for sale is, appropriately, on the twin domain name domains.domains. That site includes the domain names navy.navy, gives.gives, cheap.cheap, organic.organic, apartments.apartments and others. There are a number of domain twins listed for sale on Uniregistry. Most of them are make offer, but a couple of priced ones are vip.vip at $388,000 and club.club at a buy-it-now price of $5 million. Final Thoughts I don’t personally own any domain name twins, but I think the concept is both cute and memorable. For the right end-use fit, I can see them as having high value and utility. In doing research for this article I wondered who owns twins.com. I was expecting it might be the Minnesota Twins baseball team or some site related to the Twin Cities. But it turns out that the name is owned and lightly used by a pair of real twins. The story behind the domain name, and Major League Baseball’s attempt to obtain it, is written up several places including this article at Grantland. The domain twin edu.edu is under development. This surprised me, as I expected the educational restrictions on the .edu extension might have precluded use of this domain name. I could not find use of many domain name twins including org.org. Remember that if you do own a domain twin, it also could be used as a domain name triple by employing the third-level domain. For example, if you owned fun.fun then you could also use the third level to set up a site fun.fun.fun if you wished. I am sure that I overlooked some great domain twins in this article. I hope that readers who know of additional examples will mention them in the replies. Please add overlooked domain twin sales or domain twins in use. Have you ever owned or sold a domain name twin? Share any domain twins that you currently possess. How positive do you feel about domain name twins? What do you regard as the most valuable domain name twin?