Events at random locations
Have events that drive players to a location for specified amount of time.
Example: "Graveyard Smash" All enemies at the Forsaken Graveyard will drop extra paper for the next 5min.
This gives players a reason to drop what they are doing and head to the location of interest, encouraging PVP fights and adding flavor to the game.
I would imagine an alert system similar to the golem alarm.