These are the only kind of physical books I buy. I can read a novel or most non-fiction on my Kindle just fine. But the Kindle sucks for quickly jumping through pages, or pages with images, charts, or equations. Also you can't lend the majority of Kindle books, and even then it's only to someone else's Kindle account. I love lending out my tech books to friends. I just lent my copy of Mastering Regular Expressions to someone in my office for like the tenth time.