Patent ID: 8443043

Claim:
A content sharing system for managing, by controlling distribution of contents toward user terminals from a content distributing apparatus for groups each composed of a plurality of users, sharing of the respective contents in the group, the content sharing system comprising: a content distributing unit that distributes content data to a user terminal in accordance with a download request from the respective user terminals connected to the content distributing apparatus via a communication network; a storage unit that stores a download history of a content via the user terminal by the respective users while associating the download history with user identification information and also stores identification of each of one or more groups to which the respective users belong while associating the identification of the groups with the user identification information; a group determination unit that determines a group to which a user accessing via the user terminal belongs; a sharing control unit that determines whether a content that was already firstly downloaded by another user belonging to the determined group, the first download being accompanied by a payment of a cost, exists on the basis of the download history, and permits secondary download of the content firstly downloaded by the another user to the accessing user terminal, upon existence of the content firstly downloaded by the another user accompanied by the payment of the cost, the secondary download not being accompanied by a payment of a cost by the user; and a particular content determination unit that determines whether an in-group user belonging to a particular group selects a particular content and performs download accompanied by a payment of a cost; wherein the storage unit further stores information related to a first restriction removal condition applying to a ease where an out-of-group user who does not belong to the particular group is permitted to perform secondary download via the user terminal of the particular content downloaded by the in-group user accompanied by the payment of the cost and stores, in response to the download of the particular content by the in-group user accompanied by the payment of the cost, identification information on the in-group user while associating the identification information on the in-group user with identification information on the out-of-group user; and wherein the sharing control unit further determines whether or not the first restriction removal condition is satisfied in accordance with an access by the out-of-group user, and permits secondary download to the accessing user terminal of the out-of-group user with regard to the particular content downloaded by the in-group user accompanied by the payment of the cost, upon the condition being satisfied.