On Leanpub, the author gets 90% royalties minus 50 cents per copy. So, on a $10 book, the author gets $8.50 (85%) royalty, and on a $20 book, the author gets $17.50 (87.5%).

Just because publishers have historically paid 10% royalties does not mean it has to be that way in the future.

So, questions of copyright should be a debate about what is fair based on a range of arrangements. Personally, I'm in favour of 14 year copyright, not the "author's death + 70 years" madness that exists now...