Very very rarely. 95% of the books I read are ebooks. Most of those I read on my phone. I'm rarely without my phone so I usually have some sort of book (hundreds really) on hand. I'm a huge fan of ebooks and mostly moved away from reading "real" books. Most of the physical copies of books I read these days are my son's books. I just find ebooks more convenient. They take up less space, easier to find what page you left off on, and I can literally read them any time regardless of it is completely dark out or not. So yeah, as long as I've got my phone next to me I've got millions of worlds to explore.