$25 to Australia
One time, an online store was offering a plane ticket to Australia. To score the tickets, you had to spend more on their products. This company was also offering $25 gift certificates at the time. And if you know anything about gift certificates, you already know where this is going.
One savvy shopper purchased a $25 gift certificate for themselves. They used it to purchase more $25 gift certificates. Every subsequent purchase was registered as a unique transaction by the company. By doing this a zillion times in a row, this person spent just $25 and bought a zillion gift certificates, making them the “biggest spender” and winner of free tickets to the Land Down Under.