5
A haunted house, the real kind
Multiple promotions have offered a property with a documented history nobody wanted.
Properties with grim histories are hard to sell, in several US states they are legally "stigmatised" and must be disclosed, so owners have repeatedly turned to contests and raffles to shift them.
The most consistent version is the essay contest: pay a small entry fee, write 200 words on why you want it, best entry wins the house. Skill-based contests are structured this way precisely because the skill element keeps a paid entry lawful where a random draw would not be.
These frequently collapse. If not enough entries come in, the organiser usually has to refund everybody or award a cash prize instead, which is why almost every one of these has a minimum-entries clause buried in its rules.