[Mock8800]

Activity contest were better for people who play the game.
Luck based is best for those who are less active.

Zen should do two separate contest you pick which one you want to be in. The activate one would give a item as a prize, the luck one would give donation days as a prize.

Those who are more activate would be more likely to use and want a item.
Less activate peolpe are less likely to donate. So donation days would be a fair prize for them.