Marriott took the airlines' playbook and priced every room by the night it would die

By the late 1980s American Airlines had spent a decade proving that yield management — forecasting demand and dynamically fencing discount fares behind advance-purchase and Saturday-night-stay rules — could add hundreds of millions of dollars a year without adding a single seat. A hotel room is the same perishable asset as an airline seat: unsold at midnight, that night's revenue is gone forever, and it can never be resold. Hotels had nonetheless kept pricing rooms the old way, with a single rack rate and blunt discounting, because nobody had built the forecasting discipline the airlines had.

Marriott's rooms division carried the same problem at a much larger scale than any single carrier's fare grid: thousands of properties, each with its own local demand curve and competing pressure to just discount empty rooms rather than model who would show up and pay full price later. The obvious answer — cut rates harder whenever occupancy looked soft — treated every empty room as a loss to minimize today rather than inventory to be sold at the right price to the right guest.