Final answer:
Dan improved Mark's experience as a customer by addressing the issue of confusing line-ups and implementing floor markings to guide customers. This resulted in improved efficiency, reduced customer complaints, and reduced stress for the staff.
Step-by-step explanation:
Dan improved Mark's experience as a customer by addressing the issue of confusing line-ups. He listened to customer feedback and sought out solutions from the customer service clerks. To resolve the problem, Dan bought floor markings to show customers where to line up for each cash register.
As a result, during subsequent high traffic periods, there were no customer complaints about line-ups and the customer service clerks reported reduced stress. The store also served a higher number of customers on a daily basis because of the improved efficiency.