a db registration - updating unit registers , in a patron management db , the behavior history of each player in association with camera ids that identify the cameras that have captured images of the player . on the basis of information in the patron management db , a potential player - determining unit considers a player , whose length of stay in a specific corner is longer than a prescribed period and who is not playing , to be a potential player who wants to play but is unable to play . an attention level db management unit registers , in an attention level db , the points proportional to the lengths of stay of potential players in said corner as the attention level by cumulatively storing the points for each game console . an attention level display control unit displays the information on the players &# 39 ; attention level that is registered in the attention level db .