> was any previous non English one word io sales
.io domains are very popular within two industries: tech startups and multiplayer web games.
The whole ".io game" domain craze started with the game AGAR IO in 2015. The developer (Matheus Valadares) released his game on 4chan, and users just connected to an IP address at the time. He didn't have a name for the game yet, but he wanted it related to cells, spores, or viruses. Problem was, the really good .com's he wanted were taken. A random user on 4chan recommended AGAR since it was a simple name, and the .io domains were really cheap at the time.
Despite the name, it was a huge hit and he later released a mobile version 3 months later. During the first year, the developer made $200-300,000 USD per month from the mobile version alone, and about the same from the web version. It grew even more.
Around the same time in 2016, he launched "DIEP IO" and stuck with the same simple name and .io domain convention due to Agar.io's popularity. Just a few months before it's release, though, Slither.io also launched, and it also exploded into a viral hit. During the first 3 months of operation, Slither.io cost $15,000 per month in server costs, but the developer was pulling in $100,000 USD per DAY in ad revenue. It grew rapidly, but I can only confirm the initial revenue figures that he shared.
Generally, ".IO GAMES" are supposed to be HTML5 web-based multiplayer games where the player can join/leave a real-time game at any time. Revenue is through a combination of static ads on the front page, and interstitial ads between player deaths. However, it has evolved into .io games that are match-based, collaborative multiplayer games, shooters, and even single player puzzle games using the .io nomenclature to attract casual gamers. IAPs are also available in a small number of these web games, like purchasing skins, ad removal, or various in-game currency or upgrades.
Because of their international appeal, .io games are very popular in most non-English speaking countries. .IO games are huge in Spain for example. I have a web game that's very popular in Russia too. Although it's an English word, most of my traffic is from .ru players.
Generally, .io web domains are sold privately to game developers or companies investing in HTML5-specifically web games. It has replaced Flash, which is not recommended to use anymore due to it's significant security risks. There are even owners of web game aggregators that have been purchasing .io domains privately to be used for game development later, or even for investment, to re-sell. The web game industry is much bigger than people realize, and it's continuing to grow steadily. With better browser apps on mobile devices, it's possible that web games could replace native apps specifically in gaming because of their universal compatibility.
Hope this helps!