A network game server performs exchange of data with a terminal device employed by a user through a network. Prediction data made by a user in respect to predicted content regarding some actual phenomenon that will occur in the future is received from the terminal device. The received prediction data is registered in association with the user. The phenomenon that actually occurs in regard to the prediction data is acquired as result data and, if the result data and the prediction data satisfy a predetermined condition, prescribed points are awarded to the user who created the prediction data in question and the user is provided with value data having a prescribed value in accordance with these points.