7
A town's worth of free rent
Promotions that pay your mortgage for a year, and the small print that decides what that means.
"We'll pay your mortgage for a year" is one of the most effective prize framings ever devised, because unlike a car or a holiday it maps directly onto the thing keeping people awake.
It is also one of the most heavily defined. The rules will state a monthly cap, a total cap, and whether the money goes to the winner or straight to the lender. Those three details change the prize enormously and are always in the rules and never in the advert.