Players of a game have some discretion about how frequently they play a game and for how long. Players often lose interest in a game and cease playing altogether at some point. Before that happens, however, there may be noticeable indications that their interest is waning. Such indications are extremely useful to game providers who can detect waning interest and react to it on a macro level with new content or on a per-player basis via customized incentives for continued play.
We determine the average player interest curve by calculating each player's sequence of play sessions from their first session to their last recorded session. This is a player's play history. Since each player may progress through his or her game interest at a different rate, we normalize each of these data sets based on the duration each player is active on the server. We then examine the average session times and session interarrival times of all players throughout their playing careers. Figure 5(a) shows that player session times are relatively constant halfway through their play history and fall off to just more than 50% of the initial session time before the player loses interest completely. Figure 5(b) shows that the time between player sessions is minimized before the halfway point and increases steeply until the player's interest has fully waned. The variance on this data is extremely high, due in part to the fact that players only spend a portion of their time on this single server, and therefore this data is unsuitable for predicting the interest of a given player. However we believe this methodology can be used for games with a centralized session-tracking authority as an early indicator of peaking player interest and that game publishers should use these measurements to trigger the delivery of new content or incentives for the individual player.