I don’t understand your side note. Bitcoin is a payment network, not a distribution network so it would still require technical/manual investment from the auth

I don’t understand your side note. Bitcoin is a payment network, not a distribution network so it would still require technical/manual investment from the author. From what I’ve heard, there are some decentralized distribution platforms being created on other blockchains, but ignoring those I can’t see a reason to consider a payment network as a solution to a distribution problem - what the author needs is a distribution system that will serve his pdf in exchange for payment, and likely wants to treat payments as an abstraction. It would be trivial to build a system using Bitcoin or other blockchains that would generate a unique download link to the book, but then the author would have to be tech support for any customer that ran into problems.