Today’s most groundbreaking companies challenge established markets and competitors with innovations that dislocate and reinvent entire industries. These companies set new standards for customer experience, quality, functionality, and service, and incumbents must skillfully manage their business and customers in order to compete. Innovators can be categorized as either challengers or defenders, and almost all are better in one area than the other whether they know it or not. Defenders optimize every opportunity to grow revenue from their existing customer base; challengers devise inventive business models and make competition obsolete. Few managers excel at both.