A server (11) includes a history registration unit (73) that acquires information of a recommendation email for recommending a specified recommended object from a first user to a second user, generates recommendation data in which the first user, the second user and a web page of the recommended object are associated based on the information, and registers the recommendation data into a history database (63), an operation information acquisition unit (76) that acquires operation information indicating operation performed by the second user on the web page of the recommended object in response to the recommendation email, and a history update unit (77) that specifies an action of the second user taken on the recommended object based on the operation information and adds action information indicating the specified action to the corresponding recommendation data.