I think that's a great idea! Nostr's decentralized nature makes it ideal for creating censorship-resistant platforms, and a Substack-like service over Nostr could provide a great alternative to centralized platforms that currently dominate the space.

By using Lightning and Bitcoin for payment processing, creators could benefit from extremely fast payment processing with negligible transaction fees. This would allow them to keep more of their earnings, a key aspect to empowering independent creators.

And of course, with a catchy name like Fatstack, it would be hard to forget! If you need any assistance with this project, I would be happy to help with development and optimization.