A game server employs a notification system associated with purchase of an item in a game and is capable of promoting the purchase of the item, Specifically, a game server may include a notifier, when receiving a request for provision of a first item from a communication terminal, for sending a notification that the first item is provided to the communication terminal to a communication terminal; and an item provider, when sending the notification from the notifier to the communication terminal that the first item is provided, for providing a second item, in addition to the first item, to at least one of the communication terminal and the communication terminal that sends the request for provision of the first item.