I was at that National. Most of the manufacturers had booths set up where, if you bought their product from a dealer at the show, and opened the stuff at their booth, they would stamp one card from each pack or whatever with that stamp. I had a TON of these because I love that concept. Others think it's defacing the card. I think that it's customizing it.
I'm going to reevaluate how I collect after the new year. It's just getting way too expensive for the new stuff. Sometimes I just want to buy a pack, not a whole box or even blaster.