I'm sure no one is surprised to read this, but I delivered newspapers as a kid. When we lived in Missouri, I delivered the St Joseph News-Press and Gazette. The circulation department always had these contests. To get the kids on board, they'd pay us $10 for a new subscription plus give away lots of great prizes for those that sold the most 5 week prepaid orders.
While the subscription cost $2.25 per week to the subscriber back then, it only cost the carrier $1.15 per week. The difference was how we got paid. It didn't take a math genius to figure out that them giving me $10 for an order that cost me $5.75 was a winner.
They ran these contests about every two months. I won every one. Then someone in the home office figured out that I had more subscribers than I had houses on my routes. They were not amused.
I had already won bicycles, AM/FM radios, savings bonds, gift certificates, and lots of other great non-cash prizes. I did the same in Ohio when I delivered the Akron Beacon Journal but their margins and prizes weren't as good.