Yes, this is exactly what they started with in 2011, see the launch post: https://news.ycombinator.com/item?id=2406614

> Over this past weekend I had the idea to build a sort of link shortener but with a payment system built-in. There have been many times in the past where I wanted to share a link - on Twitter or just through IM with a few friends - but did not want to go through the overhead of setting up a whole store.

All the same comments as here, but I suppose they ultimately pivoted away from the link format. I suppose it's the perfect MVP though!

Those were different times. There’s no more room for scrappy products like that now. You can’t just post an explainer video with an email sign up and expect to become Dropbox.

Lean startups have been rejected in favor of “Do all the big work up front and then we’ll see if we like it”. It’s MVP fatigue.

No. Gumroad hosts and sells digital products from a store.

This site...well, I can't even tell what it does aside from creating a paywall link that requires $X to bypass. And on that payment page there's no hint as to what you're buying.

And after you've gotten a new link...then what? Someone can just post that link everywhere? Or is there some kind of API that unlocks a link? Or...?

The service has very questionable usability. Gumroad has obvious utility. That's the difference.