Yes there is. The same way there is money to be made in providing premium content. You could pay for extra capacity, bandwidth, fault tolerance, indexing, archiving, and many other desirable properties you'd need out of your messaging layer.

Instead the convoluted strategy by the higher-ups destroyed the entire thing. They thought they could make money with ads and "promoted content" but they somehow managed to fumble the execution of that one as well.

I think this is the Medium strategy. I think there is a mid size business in it, but one that's hard to defend and will see margins erode with time.

There is absolutely no "moat" in Twitter being a protocol.

You'd be surprised what happens when you become a hub and start seeing the effects of 3rd party integrations. That aspect can be turned into a moat if managed properly.

I think you are right but there's a time and place for it. I don't think it can save Twitter at this point but could have created a healthy ecosystem if timed well.

But it's very hard to time this well. Even Facebook and their apps ecosystem didn't create enough of a moat.

Well, Facebook's "app ecosystem" was dominated by Zynga. For a long time, Farmville was the top app and it was the only app that Facebook's highest engagement users interacted with. As such, when Zynga went downhill, it took the entire ecosystem with it.

If it was a truly open API layer, I could get these things from third parties. If it's not truly open, nobody would commit to using it.

The only people who win with ads are those who make money already and don't really need the ads. It's not worthwhile.

Well, where's the money in email? Services, right? The reason Twitter didn't go the same way as email is because it's centrally controlled and hostile to services, in my opinion.

Are there any pure-play free email providers?

Yes, the ones where you pay with your content.

I can think about at least a couple of services that do it out of sheer altruism or for political reasons (like Autistici or Riseup) and don't mine your content.

Interesting, I never heard of them.

Degooglisons-internet [1] is an initiative (broader than just email) to promote free services without selling your data. It aims at giving easily deployable apps so more hosters can appear.

[1] https://degooglisons-internet.org/

Are these stand-alone, or in a company with other service offerings?

If they control the pipe?! For sure there's ways to make money

Exactly, you can't put ads in a protocol.