The reason: invention works well where differentiation matters. In the company’s early days, the hardware that powered Amazon’s data centers was not the point of differentiation with the customer—creating a compelling book-buying online experience was. Whereas with Kindle, as we will describe in chapter seven, others were selling e-books, so there was real value in owning and controlling the creation of an outstanding device for our customers to read them on. Differentiation with customers is often one of the key reasons to invent.