Barely has the hype from the launch of the iPhone 5s and 5c subsided that chatter about the iPhone 6 has begun. A larger screen size is rumored. Apple’s product innovation strategy places it on a punishing treadmill. If the company does not deliver new products or new features to the market’s expectations and calendar, investors get jittery and the stock price sags; competitors attempt to steal the lead, and to set a faster pace of innovation. Apple’s brand and customers’ loyalty to it may cushion the dips between new product introductions and help it to fend off the attacks of competitors and the demands of aggressive shareholders, but management is still held to a relentless pace of innovation. It must deliver or move over.