A minimalist black-and-white illustration of a bespectacled traveler standing alone in front of a low airport terminal, looking at his phone as he weighs a booking decision.

Only 3 airline seats left? Prove it.

Only 3 seats left at this fare. Booked 17 times today. A clock ticks down beside the price. If you are booking a holiday trip, you have surely seen the warnings. But do any of those numbers actually mean anything?