Apple has built its success on integrating its devices and services tightly within its walled gardens, but its rivals have failed to emulate the trick and have struggled with the perennial dilemma – keep content and services exclusive to their hardware in order to boost device sales; or push it out to as many gadgets as possible? Some, like Amazon, have tried to have the best of both worlds, optimizing the experience of applications like Kindle on its own hardware but making them available everywhere. Perhaps the biggest dilemma of all has faced Sony, which was so protective of its PlayStation brand that it did not even allow the famous name, and gaming content, to be extended to its own…