• The article discusses a "sale trick" used in playing card sales, where magicians or card enthusiasts offer a special deal or "sale" on a deck of cards to entice customers. This trick is designed to create a sense of urgency and scarcity, making the customer feel like they are getting a limited-time offer or a rare opportunity.

• The article explains that the sale trick is often used in conjunction with other marketing tactics, such as creating a sense of exclusivity or offering a limited-edition product. The goal is to make the customer feel like they are getting a unique and valuable item, even if the actual value of the product is not significantly higher than the regular price.

• The article cautions that while the sale trick can be an effective sales strategy, it is important to be transparent and honest with customers about the true value and availability of the product. Deceptive or misleading sales tactics can damage a business's reputation and erode customer trust over time.