Well, first of all there are so many people that consider this as a bad thing both for your health and intelligence, it's not the same thing as a real book of course but let's admit that sometimes it can be a very good choice too. It's easier and more comfortable to take with you, especially when you're travelling. You can just take your ipad or laptop from your bag, open it, and start reading during your flight. You will spend your time wisely, become more intelligent and enjoy your time in general. I admit that electronic book will never replace real one, but let's say that sometimes we can replace them because we're living in a century of technology and we just can't avoid technological developments and bigger opportunities that world offers us.