How to NOT implement a promo code
A promo code is a code used to participate in a particular promotion. Let’s consider a practical example. Imagine being a retail chain selling products, and we want to allow our customers to participate in a survey about the quality of our service. In exchange, they can receive a reward (such as a discount or a free product). However, we want this survey to be completed only by those who have actually made a purchase. To achieve this, we can print a unique code on the receipt, which the customer can use to participate in the survey. This code is the promo code.