As a "smaller author" who used Leanpub (not affiliated with them, just a satisfied customer – both reader and writer) to publish my Emacs Lisp book I can say th

As a "smaller author" who used Leanpub (not affiliated with them, just a satisfied customer – both reader and writer) to publish my Emacs Lisp book I can say that I don't care about putting it on Amazon, and I don't think I lost a lot (or anything) because of that. OTOH, I published this book after about 7 years of weekly blogging, mostly about Emacs, so I think that everyone who might be interested in my book could easily know about it. And an intermediate Elisp textbook is rather a niche thing.