Wharton professor David Robertson discusses a "third way" to innovate besides disruptive and sustaining innovations. He outlines this approach through the examples of companies including LEGO, GoPro, Victoria's Secret, USAA, and CarMax. It consists of creating a family of complementary innovations around a product or service, all of which work as a system to carry out a single strategy. Robertson's the author of "The Power of Little Ideas: A Low-Risk, High-Reward Approach to Innovation."