You can save thousands of books on an e-reader, so you don't have to carry around heavy books. It's easy to take a smaller e-reader with you on the go in your bag. That's useful if you often read on the train, for example. Usually use your e-reader at home? A larger screen is more comfortable. Reading in the bath or next to the pool? Choose a waterproof e-reader. If you listen to many audiobooks or podcasts, an e-reader that supports audio files is useful.