You can list your domain name on marketplaces such as Sedo.com, Afternic.com, and DAN.com (inbound).
If your domain name targets a specific industry, you can try to find potential buyers and reach them (outbound).
X.com is one of the few single-character domain names that created before IANA’s restriction of single-letter and single-digit domain names registration in December 1993.
Summary:
Domain extensions are generally made up of two categories: gTLDs (Generic Top-Level Domains) and ccTLDs (Country Code Top-Level Domains). With 150 million domain name registrations today, ccTLDs make up 40% of the total domain name industry.
When the DNS (Domain Name System) first entered into operation in 1983, only the characters in the Latin alphabet were allowed to be used. With this system, although the characters of different alphabets could have a place in the DNS, web browsers and e-mail clients were not supporting such usage. By way of IDN (Internationalized Domain Name), that was first introduced in 2000, characters in non-Latin alphabets began to be available to use. Thereby, domains in almost all languages started to be registered. Until today 4 million IDNs were registered.
"We have analyzed the domains of Fortune 500 companies, to gain insight into their domain preferences. As data were gathered, some interesting facts also got revealed. For example, 14 out of the first 100 registered domains are being used as the official websites of certain Fortune 500 companies today.
494 out of the Fortune 500 companies, which roughly represent 99%, use domains with .com extensions. We see on an interesting side-note that all three companies that use .net extensions operate in the health industry. The extensions that appear only once on the list are .org, .xyz and .technology. An investment consultancy organization TIAA has preferred to use tiaa.org. 22nd on the list and Google’s parent company Alphabet’s name goes well with its domain, abc.xyz. 374th on the list, DXC Technology similarly complements its name by using dxc.technology domain."
First ever domain was registered in 1985. Many others were kept being registered since then. But what are the first used domains up to these days?
Almost all of the first registered domains were the ones registered by companies to reach out to potential clients. Registering a personal domain and setting up a personal website was not very popular at that time. Some of the companies that registered these domains were sold, some went out of business, yet some of those domains are still being used by their first registrars. In fact, it is possible to encounter some of those domains on some domain sales platforms.
One of the most interesting aspects of these domains is that some of them have not changed their homepage since day one. You may feel nostalgic on your first visit to these websites.
We have ignored some of the extensions on the list. If we were to count the domains with .edu extensions that were registered for every higher education institution during the inception of the internet, we would end up with a meaningless list of identical entries.
Overall, when we look at the ownership status of the domains, we see that 53 of them still belongs to their first owner. On the other hand, while 24 out of 47 domains have changed hands directly, 23 of them did through the acquisition of the company that owned the domain.*
What is surprising is that 5 out of the 100 hundred domains in the list are on sale as stated on domain sales platforms, as well as their respective homepages. In other words, if you are willing to pay enough money, you may own one or several of the 100 oldest domains of the history of the internet.
Those domains that are not on sale and have no public record of sales history are generally the ones used by old companies for their official websites. We may say that established technology companies like HP, Intel and IBM are among these. Additionally, we notice that some domains have been welcoming their visitors with the same homepage for quite some time and look abandoned.
34 years ago today, the first domain name symbolics.com was registered by a company called Symbolics Computer Corporation. More than one billion domain names were registered since 1985.
You can also check the popularity of any keyword on the trends page: https://dofo.com/trends/keyword/coin
It says, how popular is the keyword, how many registered domain names exist with that keyword, what percentage of these domain names are used actively as a website and more.
As for the registrars; yes Godaddy is the first one with about ~70 million domain names under management and Namecheap and Tucows are following it: https://dofo.com/registrars