This is a true statement. As a former Revenue Manager, here are a few reasons why no-shows can actually cost the hotel money through lost revenue.

• Ancillary Revenue: While not every guest provides ancillary revenue (food/beverage, parking, etc), a no-show guarantees that the hotel will not make any extra profit for that room.
• Displacing Another Guest: The hotel may have been able to sell the room to a someone else. That guest might have also stayed for several nights. Note: This can happen even when the hotel is not sold-out. The no-show room may have been the last available room with a specific bed-type. Or, it might be the last base-level category. (Some corporate clients might have a policy to purchase only base-level rooms.)
• Employee Compensation: Positions like Bell Staff and Food/Beverage are paid via tips. Those employees can't earn any money from a no-show.
• Staffing Levels: For departments like Housekeeping, staffing is a function of the total expected occupancy on a given night. While a single no-show wouldn't matter, multiple no-shows means a hotel is overstaffed. (In one hotel in which I worked, we would occasionally have 12-15 no-shows in our 360-room property.)
• Disputed Charges: Despite being able to prove that the reservation was valid, there is a decent chance that a credit card company will side with the guest in a dispute over a no-show charge. In that situation, the hotel will lose all revenue plus the labor cost association with the chargeback.