This is the story of how CodePen aquired CodePen.com, after many years of not owning it.
In the beginning, I think we just didn't care. This was a bit of a hobby project. We bought the domain at a time when we still mostly were thinking of this as a self-install project, and only bought the domain to have an example installation that you could alternatively use.
We thought .io is a cool top level domain (input/output, perfect for CodePen), despite the dark side (for which we are benefactors). We still think that. More, we've never had any trouble with it. People seem to remember it. People seem to be finding it. SEO seems fine. The only big feedback we get is that people get "Codependency" as a search auto-fill when typing it in browser bars, and there isn't much we can do about that!
CodePen.com was owned by someone else. Someone who was using it, sort of, as a placeholder for a coming-soon CMS. I still don't entirely understand that story, but recently, that person reached out to us asking if we wanted to buy it. They could re-brand themselves as something else, and we'd essentially be paying for that re-branding.
We were interested, of course, but this kind of thing is a process. We had to figure out where we stand on it as a company, which meant plenty of talking. We had to get advice from trusted sources not close to the issue. We had to negotiate, and get advice on that negotiation (I'd probably leave a used car lot paying more than sticker price).
The advice we got was sound. There was lots of it. Stuff like establishing trust by owning it. Stuff like... if we could "deploy" the cash to drive growth, we should do that instead, but since that was unlikely, buying made more sense. Even our investors agreed.
The negotiation we did was largely successful. We got the domain.
What to ultimately do with that domain is another issue. For the moment, it just redirects in the simplest way possible.