Just - in general, and as others have stated, they're just better. Yes. E-readers are better than paper books, except anything that is a "picture book". Graphic novels, and photograph books. There is no back-light to hurt your eyes, there is no "refresh rate". You can adjust print size. They are very light, compact, and easy to carry anywhere. Some have robotic text-to-speech if you want to plod along a book while driving. They remember your page, new books cost less, there is a ton of free content available, you can get a book instantly where ever you are, and you can store 1000's of books on one - so you have access to whatever book you want when ever you want it, and there are no boxes of used unwanted books all over the place. It remembers the last page of any book you've read - no more folding pages, losing book markers, or losing your place. No more "lost" books. They hold a charge a ridiculously long time and charge up quickly... and last but not least they don't kill trees and good ones are affordable now.
Paper books that are mainly text? No advantage to them whatsoever. None. They'll be gone before film is. Everyone who resisted eReaders, including myself, did so because they "like the tactile feel of books, the smell, turing the page..." blah, blah, blah... You get past that in two seconds.
