Mainly, in some cases, printed books still have an edge in usability over e-books. Some of it is just due to current technical limitations: e-books often have b

Mainly, in some cases, printed books still have an edge in usability over e-books. Some of it is just due to current technical limitations: e-books often have bad enough typography that the reading experience is noticeably worse than with a printed book. Moving around the content is still more awkward with e-books than with printed ones. We also have adopted page numbers as reference markers and haven't yet gone back to numbering sentences or paragraphs in most instances. There's also the issue that CDs or DVDs are useless without a playback device, while books are self-contained.