While many businesses extended credit to their customers, Diners Club allowed cardholders to use a single credit card at multiple businesses.
In 1950, the first Diners Club cards were given out to 200 people, mostly salesmen who often dined with clients, and could be used at 14 restaurants in New York City.
Here's the official story: In 1949, Frank McNamara schedules a business meal at a New York restaurant called Major's Cabin Grill. Prior to dinner, he changes suits. After dinner, the waiter presents the bill. Frank reaches for his wallet...and realizes that he has left it in his other suit. McNamara finesses the situation, but that night he has a thought, "Why should people be limited to spending what they are carrying in cash, instead of being able to spend what they can afford?" In February 1950, McNamara and his partner, Ralph Schneider, return to Major's Cabin Grill and order dinner. When the bill came, McNamara presents a small, cardboard card - a Diners Club Card - and signs for the purchase. In the credit card industry, this event is still known as the First Supper.
By the end of 1950, Diners Club had 100% of the credit card business, with 20,000 customers, and was accepted at over 1000 restaurants. By the end of 2006, Diners Club (now called Diners Club International and owned by Citibank), had less than 1% of the credit card business.