183. Marketing strategists at a major video retailer are discussing ways to increase revenues by boosting mid-week DVD rentals, which generally fall far below weekend rentals. One plan to accomplish this is to extend the return date for DVDs rented between Monday and Wednesday so that customers may keep them until Friday. Since more customers will return to the store on Fridays, they will be also be more likely to rent again for the weekend.

Which of the following, if true, would indicate the most serious weakness in the plan above?