Meet Marge and Jerry Selbee, owners of a "party store" in Evart, Michigan that sold cigarettes, liquor, and lottery tickets. After watching thousands of customers, Jerry figured out how to hack the odds in a certain type of lottery: called Winfall in Michigan, and later Cash WinFall in Massachusetts.
Play a dollar here and there, and you might win occasionally. But play thousands and thousands in particular weeks, when the prize accumulated in a certain way, and Jerry realized you could almost guarantee a profit to the tune of five or six figures.
So that's what the Selbees started doing, to the point that playing the lottery became a full-time job at times. Over the course of nine years, it worked, to the point that their estimated total lottery haul was almost $27 million.