I used a Kindle, but get the lion’s share of my ebooks from Anna’s archive. Books are often delivered to my Kindle through the email to Kindle service.

I have no illusions that every single book I read is fed through Amazon’s data machine. The Kindle estimates the time to completion of a book based on your reading speed - everything that it could possibly interpolated from your reading… Will be. And you can bet it will be sold, or at the very least advertised to you on Amazon.