To perform effective advertisement to a user utilizing a network.

As shown in drawing (a), users (user A, user D, ...) whom user B has registered as a friend in advance to a server, each user's circumstances, that is, whether it is online or not and an icon (game C, game A,...) showing a playing video game or the like are displayed at a user B's terminal. When user B clicks "game C" of "user A", user B's terminal performs advertising information display treatment. By this treatment, an advertising information screen 231 is displayed at a part of a display screen of a terminal 1B as shown in drawing (b). In the advertising information screen 231, advertisement relevant to circumstances ("Game C") of user A whom user B has registered as a friend is exhibited. Since it is supposed that degree of interest of user B to the advertisement is high, high advertising effect can be exhibited.