Or let's assume they lost $5. They just paid $5 for the opportunity to impress 4 people and gain 4 regular customers. $1.25 to bring a human into your business

Or let's assume they lost $5. They just paid $5 for the opportunity to impress 4 people and gain 4 regular customers. $1.25 to bring a human into your business isn't that expensive, especially if they actually showed up. If you divided the cost of a billboard into how many people walked in the door, it may cost you much more.