Originally .io is a ccTLD assigned to the British Indian Ocean Territory. I have a doubt though that any of the registered .io domain in the Alexa top million is utilized to promote local services. Oppositely, possessing a nice sound and being short, .io is recognized as generic extension by the developers, users and Google. Developers changed the meaning from Indian Ocean to input/output. With the emerging new web technologies, web applications become more popular than operating system dependent softwares. These web applications and services request inputs from the user and provide some output result at the end. Thus, web app developers are almost screaming for an extension like .io. Especially when .com is so much oversaturated that there is no chance to get a short and meaningful .com for reasonable price and small start-ups don’t want to spent half of their budget on a single domain. The not yet released new gTLD, .app is looking to be the extension of this field but being late its chance to win is decreasing and .app should defeat .io to get this market.
The break-trough of .io happened this year, see .io sales above $2,500 in 2015 below, topped by cloud.io that was sold for as much as $45,000.
Many consequences can be drawn from these sales.
First, .io is really for the web applications field but non-technology .io domain prices also start to grow, e.g. movie.io, art.io and karma.io were sold for thousands.
Second, break-trough of .io is catalyzed by Flippa. It is not surprising, since there are many web developers on Flippa and they value an .io domain for more. Many of the .io domains in this table were Editors’ choice on Flippa which maximized the visibility and sale price of these auctions.
Third, and most surprising fact is that in the technology sector, .io is maybe the second choice extension after .com. The highest sale “word”.net in 2015 was checks.net for $24,500, which is half of the price of cloud.io – and most probably cloud.net could not be sell for that high now. It is easy to explain: with .net, you admit that you can’t get the .com. With .io, you are cool and it seems like you never considered getting the same domain name with .com extension.
The skyrocketing popularity of .io is also evident when checking .io domains amongst Alexa top 1 million. There are 1,680 .io domains within 1 million, among those more than 200 within 100,000. The most popular sites running on .io have millions of visitors a month. CodePen.io is a popular portal collecting code snippets, ouo.io is one of the most successful url shortener, techinsider.io, fontawesome.io, spring.io, soup.io, and so many more great and popular apps and sites are running on this extension. Since .io only became popular recently, almost all websites running on this extension are fresh and modern.
Maybe the only concern with this extension is the relatively high registration fee (about $35). However, this helps keeping the extension clean, since it does not worth registering it for parking or spamming purposes. This is why so many one word and short .io is still available for hand-registration. Not for long if .io popularity continues to rise.