This is great news since it decreases the lockin / leverage that Substack has over individual writers on the platform. It's a creator-friendly choice and I respect that Substack is putting their money where their mouth is in that respect!
I was wrong. In fact, a lot of merchants saw the third-party domain as a status thing. There were thousands of merchants in one tribe and thousands in another. They are still doing it today, including at levels of commerce that prove that I was not just off, but that I totally misread the market.
People trust few domain extensions more than others even though many of them are similarly priced and available. It's all about who else is using the same extension. .com? Used by most companies. .news ? no one? not trust worthy then.
It's somewhat fascinating to me that the bigger the company, the more trust people put in their verification of actors employed on the platform. Intuitively, I would think the more actors in a company - the less trustworthy or verified the actors would be.
An argument against custom domains being a "premium" feature, then? If you don't have a paid plan, then you have to bring your own domain. Paying gets you the *.example.com status symbol. Makes sense — a custom domain usually requires technical expertise and some amount of inconvenience for users (not unlike a services company that publishes their source code to GitHub, which you can always set up and maintain for yourself, but if you want to use the company's hosted services, then you have to pay). Another part of the value proposition would be, "You're gonna have to spend money one way or another — either to a registrar or to us — so why not let it be us?"