Like was mentioned, the promoter/issuer didn't pay for the serial number option. If they don't use a serial number, then they can print hundreds/thousands of identical labels. If there is a serial number, then each label is different, hence an individual label, which means more money. Grading adds an additional fee. Are the serial numbers different on each piece? Maybe they use the same number over and over like on the "Samples" given out. The real answer is, who cares?