Manning Publishers has a liveBook offering.
And it allows for the type of mini transactions (through their self-hosted “token” system) that I proposed when writing about how I’d dumped Pi-hole last year.
Quoting from their recent announcement email
Book publishers follow a simple rule: put your content behind a solid paywall. At Manning, we believe you should be able to see before you buy. liveBook search and Manning Tokens make the paywall porous. Our new new timed unlock feature moves the whole wall further back!
That’s pretty dang cool, Manning.