There are two main considerations. The first is the potential time delays associated with transmitting large documents across the Internet. As an author you cannot assume that all your potential readers will have a fast network connection.
Many people access the network using modems.
Others are in locations that suffer from high network traffic with the delays that brings. This is in contrast to paper documents. Electronic documents on CD-ROM or available on a local area network can also be delivered quickly. The second challenge arises out of HTML's hypertext linking capabilities. People navigating links can experience problems maintaining their orientation within a linked document.