Better then creating topics, Collecting cash from each person balbala
It could be simple thing like a mini game which I'm sure players will like it even more, An npc explains about lottery then he asks for whatever the price is, they automatically will take from your cash the requesting price and you will be enter, after a time which it could be set a day or whatever, An message will show up like a yell who ever won, then the winner will come back to the same npc, and he will take the lottery money, easy and very simple better then wasting time.
O-T: Good luck for everyone