Final answer:
The trade promotion being used in this scenario is Sales contest.
Step-by-step explanation:
The trade promotion being used in this scenario is Sales contest. In a sales contest, salespeople compete against each other to achieve specific targets or goals and are rewarded for their performance. In this case, the retail salesperson at the cosmetics counter receives $5 for every bottle of Glow perfume sold, which is an example of a sales contest.