May I ask who is holding the funds? I guess the goal is to raise more money then is being given away, which is quite a lot for a new service.
Using a multisig wallet with an escrow that needs to sign off would give a lot more trust I guess.
Guess that really is the intention. OP did mention the raffle will be held after all tickets are sold. Provided they do pay up when they've collected it all, I don't see a problem.