My wife used to work those promo tables. Thats exactly how it usually ran. They work 30-90min and are forced to leave due to no product. She got scammed into working for one of those companies. It does get the product in front of the people, but I doubt its on the scale that the product sellers had hoped unfortunately. I think the only people making money at those companies are the promo owners.

Please don't take this as negative, its just fact from my personal experience.