It's also possible that there may be times when e-books will be rented rather than sold. A library, for example, might lease several hundred copies of a new blockbuster novel to meet initial demand. The publisher or bookseller would be able to provide those copies for a set period of time without worrying about transporting them back and forth. And, of course, there'd be no wear and tear on those copies. Right now, most printed books have a short life cycle.
Publishers tend to print and warehouse a book only as long as it sells fairly briskly.
Once sales taper off, it's declared out of print and is available, if at all, only in libraries and at used bookstores. By contrast, a publisher can archive an e-book for virtually nothing and deliver it to a customer or a bookseller digitally whenever it's requested. Sounds simple, but there are major stumbling blocks in the e-book's road to acceptance. They love the touch of printed books, and the feel, the heft, even the smell. And people in the book industry are largely book lovers.