In the McDonald's 2013 Monopoly game, the Boardwalk piece was so rare that the odds of ever finding it were 1 in 602,490,060!

McDonald's gave their patrons a chance to win really big prizes in their in-store collect-and-win game in 2013. Prizes included a million dollars cash, cars, and more. With the purchase of specific McDonald's products, McDonald's Monopoly game pieces could have been collected and with those game pieces, you could have won instantly or you could have collected Monopoly properties for the chance to win big prizes—like a million dollars cash.

If you managed to collect rare game pieces, you were set to win. But how rare are some of the pieces and what were the odds of finding them? Boardwalk (#452) was one such rare piece, with the prize of finding Boardwalk and Park Place being a generous one million dollars! Boardwalk was so rare, in fact, that the odds of ever finding it were 1 in 602,490,060!

The odds of finding Park Place were 1 in 11. The odds of finding the prize on a Big Mac were much better than finding both pieces. The overall odds of finding both pieces were 1 in 3,050,412,898, but the odds of finding both on a Big Mac were 1 in 37,955,000.

The collect-and-win game was only one way of winning big prizes at McDonald's.

(Source)