To provide technology for realizing contents distribution convenient for users.

In the contents distribution system, each user is charged in accordance with data volume distributed by streaming distribution (s330-s410). Since the data volume is specified as data volume stream-reproduced by a client out of contents data, only a rate corresponding to the data volume specified as the data volume stream-reproduced by the client is changed when the distribution of the contents data is ended before completing the reception of distribution of all the contents data. Since it is unnecessary for the user of the client to pay the charge of the whole contents data when the distribution is stopped on the way, a feeling of resistance to the reception of distribution of contents data and the use of the contents data is reduced and a user can easily receive the distribution of the contents data and try using the received contents data.