I know there is a lotto each week, and no one ever seems to enter, so some suggestions (I don't know if these are all possible, but hey.
Make the Tickets usable, or something to get rid of them at the end of each week. Atm, I have like 20 tickets that are just hanging around, because no one wants to buy them off me, and I can't use them again.
Put some more tickets in the shop. ATM, I am the only person selling sunshine tickets, because I bought them all. I charge more than the original price, and I don't even think some people know how to trade.
I don't know. If it's possible to link the tickets to another page, then maybe link them to a random number generator, so people don't have to make up the numbers themselves (The hight of laziness, I know, but hey.)
Anyway, just thoughts.