FEW companies are as defined by a single product as Coca-Cola. The firm has sold the sweet dark soda since 1886. At its headquarters in Atlanta, archives house the advertisements that sowed Coke in the world’s consciousness: posters urging consumers to “Have a Coke and a Smile”; Norman Rockwell’s 1935 painting of a boy fishing, Coke bottle in hand; a Coca-Cola record with tunes sung by Ray Charles, Aretha Franklin and The Who; advertisements with a red-coated, bearded Santa Claus—it was Coca-Cola that popularised the image of Santa in the 20th century. Today Coca-Cola has $42bn in revenue and is available “within an arm’s reach of desire”, as the firm puts it, in every country but Cuba and North Korea.