The transformation of the credit card created a multibillion dollar industry. IBM had perfected in the 1960s a method of adhering a magnetic stripe to the surface of a plastic credit card. This stripe could have multiple tracks and allow read and write operations from special machines capable of decoding binary data. Striped cards were first used for ticketing at O'Hare Airport in Chicago by American Airlines and American Express. The first of three tracks on early credit cards was used by the airline industry. The second track contained identifying information such as account numbers and names. The third track was read-write and could hold the balance of an account. The American Banking Association approved use of the magnetic stripe in 1971 but most banks resisted its use. In 1972, Dee W. Hock, president of National BankAmericard Inc. (NBI, later to be called Visa), adopted the magnetic stripe for its new Uni-Card division in competiton with the cards of the nation's largest banks, including Bank of America and Citibank. Eventually, the banks followed his lead and made the magnetic stripe common on all credit cards.
