When spinning a penny, the chances of landing on tails is 80%. Spinning a coin is often believed to be a 50-50 proposition. However, when it comes to the penny, the side with Lincoln’s head is a bit heavier than the flip side. The coin’s center of mass ends up lying more toward heads. Moreover, flipping a coin is not 50-50, but 51-49, biased towards the side that was initially facing up.
In 1987, an 18-year-old freshman raised $28,000 by collecting a penny from 2.8 million people. Mike Hayes, a student at the University of Illinois, came up with an idea to raise the money he needed for college tuition. He contacted a newspaper columnist at the Chicago Tribune and asked him to write his readers a simple request: send a penny. They sent 90,000 letters and about 2.9 million pennies which more than covered his tuition.
Pennies extended cash transactions by about two seconds. A joint study with National Association of Convenience Stores and Walgreens showed that handling pennies added the extra time. The same study showed that the average consumer made 23 cash transactions in a single month. That comes out to an hour or two per year dealing with pennies.