The present invention provides a content-on-demand system capable of
managing users' system-utilization frequencies such as download counts
and connection times as well as changing the quality of a content
transmitted from a server to a user in dependence on the
system-utilization frequency of the user. Thus, a high-quality content or
a highly functional content is provided to a user with a high
system-utilization frequency. By differentiating contents provided to
users in accordance with the system-utilization frequencies of the users,
network businesses can be activated.