Looks like they know what they're doing
I've gradually subscribed to about 6 of the 'newsletters' at Substack. 3 of them are writers I was already following elsewhere, and was grateful for the chance to pay for previous value.

After wandering around through a variety of topics, I think Substack has the right recipe to succeed and grow. I'm also halfway convinced that they're not playing any AP or sting games.

Other new media like Gab and Parler were obvious stings. Quora was interesting a couple years ago, but after it turned toward subscription I left. It's not clear what Quora is trying to do; I just know that it doesn't make sense, it feels wrong, and I don't want to be around.

Substack has a rep for carrying dissidents, but in fact about 70% of their content is on uncontroversial subjects like food and music; and within the hot topics, 70% of the content is strictly orthodox Establishment thinking. The dissidents are less than 10% of the total. This proportion resembles an old-fashioned pre-1946 newspaper.

Those percentages are reassuring. Despite the reputation, readers and writers who want 'ordinary' stuff are the solid majority, so it will be a lot harder for Deepstate to make the case that Substack is solely for wackos.

Maybe Substack should do more to publicize these percentages.... but it appears that both types of material are growing and profiting, so maybe they know exactly what they're doing.

The basic business model is simple and old. Pure subscription to individual writers, NO advertising. This used to be a common model for large magazines as well as small newsletters, until Google and FB turned all business into pure advertising that is "free" to the "consumers". Pure subscription naturally creates a two-way obligation loop between writer and reader, with no shaping by external forces.

The non-fungible aspect of subscribing separately to each writer is also important. You can see and sample all the wares, but your money isn't paying for the wares you don't want to buy. I hope Substack can maintain this modularity. For many years I paid large amounts of money to individual teachers through DonorsChoose, which had a similar modular policy. In 2020 DonorsChoose started issuing mandatory SCREECHES on both the "virus" and the riots. My money was no longer supporting the individual teachers; my money was officially encouraging riots. So far Substack has refrained from breaking into regular programs with corporate SCREECHES. When they do, I'll pull out.

Incidentally, pure subscription also makes a faster website. Other websites are slowed down by constant negotiation with Google-based ad servers. Sometimes a website won't load at all when one of the ad servers is slow. Substack loads instantly.
  ¶ 8:03 PM