"That can work. Have a special group just for them with a better prize than all the rest to promote it." It might be a hard sell to the teachers but it could be really fun. He loved Halloween naturally, so getting more peopled involved just seemed like more fun.
"We could, but I think most of us know one another at least vaguely. But we could group them and get them talking about ideas like we are? That way they're trying to get excited and promote the idea just like we are right now."