IMHO: .io if the site is about data/file interaction (providing info, getting something out of it) interaction.
.co if it is about a service where the service itself is the product and not a "upfront definable deliverable".
🤔 makes sense?
Could you give me an example of "upfront definable deliverable"? because I'm also considering .co, and I wonder if I should go with it.
A definable deliverable: you enter data and get a file (image/data/...) as output. Or an overview or insight.
Undefinable deliverable: you fill in information or contact the owner and you get consultancy that will help you reach your goal(s)..
I'd say it depends on the niche. From my experience .io is more associated with techy-techy products. Whereas .co is more of a generic domain.
Other people may have a different POV, tho
I already asked the similar question recently, and @manuelfrigerio gave me an answer. I hope it helps you, too!
go with IO, if you're doing anything related to IT and you absolutely can't find a .com. I faced a similar dilemma and decided to go with seobots.io, because there was absolutely nothing available in the .com zone.
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