It has already been replicated. Ghost is one example I know of that is very explicitly competing with them: https://ghost.org/vs/substack/ https://ghost.org/vs/

It has already been replicated. Ghost is one example I know of that is very explicitly competing with them: https://ghost.org/vs/substack/ https://ghost.org/vs/substack/ One newsletter I'm subscribed to recently switched from Substack to Ghost, and as a reader it was completely seamless and I might not have noticed if they hadn't mentioned it. They were able to transfer all their paid subscribers and article archive, so it doesn't seem like these services have any real moat.