“In a surprising way, it is far easier to innovate down the stack than up the stack. The reason for this is that you are yourself a natural customer of the lower layers. Apple knew what it wanted from an ideal future microprocessor. It did not have the skills necessary to build it, but the customer needs were well understood. Technical skills can be bought/acquired, whereas it is very hard to buy a deep understanding of market needs. It is therefore no surprise that Apple had an easier time building semiconductor chips than building Apple Maps.”