The idea is to have a countdown in the game itself that would show the number of days left until an upcoming limited time promotion (e.g., 63 days until this game will be FREE for a limited time). So when people tell their friends about the game, they can tell them they can buy it now or wait until the promotion. Moreover, the developer could provide a way for people to get a reminder when the promotion starts. Would something like this increase the virality of an iOS game significantly?