Young women and teens are ruthless customers, shifting from one on-trend store to another as quickly as they shift love interests. The retail clothing industry is therefore a great place to learn this vital leadership lesson: In today’s information-age economy, business model innovators emerge as winners, while those delaying business model innovation steadily lose market share. Business Week’s Benetton: A Must-Have Becomes a Has-Been tells a sad story of a retail chain I first encountered and fell in love with in the late 1980s. Founded in 1985, this Italian clothing maker brought consumers the look and feel of European clothing at an affordable price, accompanied by its bold United Colors of Benetton advertising that paralleled the bold colors of its clothing lines. By 1993 the company was 7,000 stores strong, with locations in high-end shopping malls in major US and European cities.While Benetton…