Im not sure that this had been suggested yet, but I would think it would be a great idea to add a daily consecutive login bonus.
Example:
First Day: 10 Gralats
Second Day: 30 Gralats.
Third Day: 100 Gralats.
fourth Day: 200 Gralats.
5th Day: 300 Gralats.
Sixth Day: 500 Gralats.
Seventh Day: an EC piece.
I think that this could make the players more encouraged to log in daily and could boost the games population.