A system that worked so well, the state lottery had to take action.
"It boils down to basically a giant office pool on a larger scale," said Jerry DaGrosa.
DaGrosa is the owner of a convenience store called "Jerry's Place" in western Massachusetts.
Working with an out-of-state investor, Jerry figured out that if they bought more than $100,000 worth of tickets, they had at least a 72 percent chance of making a profit.
By one estimate, 100-grand in tickets guaranteed them anywhere between $240,000 and $1.4 million.
"An investment in the lottery, hoping to make a return on the investment, it's totally legal," he said.
Legal indeed, and here's how it works. Every couple months, if no one wins the $2 million Massachusetts lottery jackpot, state officials "roll down" the money, making all the smaller prizes bigger.
So buy more tickets and your chances to score the smaller prizes goes up.
Once word got out, Massachusetts lottery officials began cracking down.