The next time you see a pair of Nikes, spare a thought for Caroline Davidson. You haven't heard of her? But you've seen her work. She designed the "swoosh" logo that has become one of the most recognisable brand images in the world. And she got paid only $35 for her design, created in 1971 when she was a graphic arts student.
It was meant to represent the wing of Nike, goddess of victory - and the story of trainers is about the victory of marketing, taking a basic product and turning it into a fashion icon - from a shoe business to show business.
When Nike started putting the logo on its shoes in the early 1970s, it was following the path set by Adidas, which had already established a strong visual image, making the brand a point of reference in its own right.
Like car marques, bank colours or gang emblems, trainer logos are about creating a sense of identity, easy to recognise, with their own personality.
And maintaining a high profile for these brands is vitally important, with Adidas spending in excess of pound;500 million a year on promoting its products.