I've regularly scored things like 70% off regular price when booking the day before.

They continue to advertise their regular full price on their official site and other mainstream sites that business travelers use.

But they advertise at a massive discount on certain discount sites that attract budget travelers.

They want to fill the rooms, often in response to last-minute cancellations, and they hope they get lucky with somebody at full price first, but they advertise budget prices on budget sites because a deeply discounted rate is better than no money at all.