In theory it keeps your business card elevated / near the top, and has more volume to be grabbed from.

I’ve only done it the one time (genuinely), maybe they were giving cookware to everyone from that morning as a show of appreciation or to make them feel special, maybe it was just luck of the draw and I’m batting 1000 in business card raffles, maybe I’m only remembering my successes (I don’t think I am), or maybe it actually worked? The mystery of 100% success makes for the better story, so I deliberately stopped the practice.

(Also I have a way to always walk out of a casino with more money than you walked in with, not significant life changing amounts of money, but enough for dinner and drinks, but I like to tell people (genuinely) I’ve never walked out of a casino with less than I walked in with, the trick is to go to the concierge desk, tell them it’s your first time there, give them your name and address as verification it’s your first time there, they’ll give you house money, ever time you hit take the money out (it takes from your winnings before taking from the house money), at the end of the night compare how much you walked away with from how much house money they gave you, and that’s how much you’d have been down of your own money, my best is about 90% of the house money I put in as cash in my pocket, me and 3 friends did this and walked out with 150$ from nothing but a little time invested, the “real” gamblers hated being behind us as we checked out dozens of winning slips each)