How much does it cost to distribute ebooks over the web? (bandwidth, server costs)

Digital libraries have the potential to store much more information than traditional libraries, simply because digital information requires very little physical space to contain it. As such, the cost of maintaining a digital library is much lower than that of a traditional library.
A traditional library must spend large sums of money paying for staff, book maintenance, rent, and additional books. Digital libraries do away with these fees. Both types of library require cataloguing input to allow users to locate and retrieve material.