To allow a user to positively use delivery information.

A win probability calculation part 107 acquires a person concerned as a user having relationship with a user as an object of win probability calculation from an inter-user relationship information holding part 105, and calculates win probability associated with the user as the object of win probability calculation according to how much the user as the object of win probability calculation and the person concerned use delivery information. The win probability of a gift increases as the users having relation ship use the delivery information more, so the user may urge the person concerned to use the delivery information.