Swift and Beyonce show the lucrative pop-fashion liaison

Stage costumes have long been a way for designers to gain massive exposure -- think of Madonna's conical breasts that helped make French designer Jean Paul Gaultier a household name in the early 1990s. From Edith Piaf's little black dress through Elton John's whacky glasses to David Bowie's many elaborate fashion statements -- music stars have often communicated with their clothes. A pop star endorsement can have an immediate impact on a brand's bottom line. Sales of rhinestone cowboy hats increased...