A food delivery platform allows a small group of restaurants…
A food delivery platform allows a small group of restaurants to offer a “Free Dessert with Every Order” promotion as a pilot test. These restaurants experience a significant increase in order volume compared to other restaurants on the platform. Based on these results, the platform decides to roll out the promotion to all restaurants. Explain why a market effect might lead to a much smaller increase in order volume when the promotion is implemented across all restaurants (external validity issue).