They most efficient Manufacturing, R&D and Marketing Company. Manufacturing - They have almost perfected it, no technical flaws, products release on time not just a few, millions of them. Once they figure out the manufacturing they stick to that design for two years. Making more money of it. They get better manufacturing price, by lending loans to buy machines etc.
R&D - The are a lean machine, for how big the company is their R&D budget is tiny. They are willing to wait to get the product right, even if they have to delay the product. Look at iPad, Apple TV etc.
Marketing - They don't spend anywhere near the amount samsung and other spend on advertising. But where they spend they are very effective.
The are launching so many products and all of them are going without a hitch. Just an example, samsung edge was having issues with manufacturing. Apple has a new display and 3D touch with new electronics in display in the new ones but they are still breaking shipping records (all deliveries will be one time). They also have apple tv and iPad pro. both expected to sell few millions launching in few weeks. They have their manufacturing oiled up pretty well
All these add to make the margins bigger.