Recently, I started buying non .com domain names here and there when I see a keyword that I think well-matches the extension. I’m not interested in sharing specifics with you, but I have bought .AI, .IO, .CO, .APP, and .DEV domain names in auction, in addition to .XYZ that I previously wrote about. Non .com domain names is a small percentage of my portfolio and a fraction of a percentage of inventory cost.
One word of caution is that some extensions have rules that need to be followed in order to use the domain name. I learned this after winning a .Dev domain name in auction at Namecheap. A day or two after setting the nameservers to Afternic, the domain name did not resolve to a landing page. I checked in with Afternic and the domain name was set up correctly there. I submitted a ticket at Namecheap to see what was preventing the domain name from resolving, and here’s what I was told: