They must not of weighed it properly when they sent it. They are charged by the ounce. Not quite sure how it works but they are sent USPS permit mail which I think allows the post office to charge the sender (IMS)extra without returning it for insufficient postage or asking you for postage due.
No sticker on mine. It is a neat look to the tickets this year. but I always fold mine an put it in my pocket, now I can't do that. We are all going to have to buy ticket lanyards now.