Customers Care A word of caution to companies that pool their customers into one queue with multiple servers: In deciding whether to join a line, customers care a lot more about line length than number of servers. Even if it’s moving quickly, a long line can put customers off, according to a team led by Yina Lu of Columbia University. The team’s study of supermarket customers showed that a line of 10 people can have a large impact on purchases, and increasing the queue length from 10 to 15 customers would lead to a 10% drop in sales.
SOURCE: Measuring the Effect of Queues on Customer Purchases