Once there's a pdf or other ebook available it'll be pirated. How that doesn't damage sales I'll never understand.
The Lazarus (object pascal ide) book is only available in a physical book format for this reason.
In another life I wrote technical books, which at the time were only available in physical formats. That didn't stop electronic versions of the more popular books from appearing on usenet.
That's a good read. It's hard to understand the motivation of someone who's prepared to put in that many hours pirating a single book. It's seems a bit pathetic