The only "magic" way to help a game be played again and again, is for it to be always providing a challenge (easy examples are multiplayer games and arcade single player games) and for it to be very well designed aesthetically and mechanically so that it's a pleasure to return to.
Although it depends on your audience, the simple and non-gamers don't need much at all to play a game a lot, as long as there is something to bait them with, such as statistical growth.