Growing an exclusive brand by moving down market can be tricky: Such efforts often dilute the symbolic value for core customers. Consider what happened after Burberry brought its iconic plaid to a host of new products (including dog leashes) in the early 2000s. Sales soared—but soon the brand’s ubiquity drew media ridicule (and a slew of counterfeits). To restore its cachet, Burberry reserved the plaid for use in linings and other discreet places. Tiffany, Gucci, and Pierre Cardin have learned similar hard lessons.