Great point. I picked up The Linux Programming Interface from a Humble Bundle, knowing nothing about it, and my first impression was "This is a terrible book: very dry and not engaging." My manager mentioned it was excellent, though, so I actually picked up a hard copy, and then I saw what was going on: it's a Linux textbook, not the kind of programming book you'd really read from cover to cover.

I know this story sort of shows my cluelessness a little, but it also shows how having the ten-pound tome on my desk gave me insights into how the book was meant to be interacted with, that the ebook didn't.