Switching cost is the moat of Apple, the longer you stay the deeper you sink

If you look at how $Apple(AAPL.US)$ design their products you will understand that they are trying to lock you in their ecosystem. From their own app store, to proprietary ports, to integration of all Apple products, to the difficulties of transferring to another product.
You will find that the more Apple products you buy, the harder it is for you to change to another product. All your cables won't work on Android so you have to buy another one. You'll also lose the ability of seemless transition e.g. your iPhone website is in sync with your Macbook.
Now Apple is trying to get into your homes, and even trying to get you to drive their car. They will be sure to make that the systems are very well integrated. They will sync up so well that losing just 1 Apple product will cause you some trouble or inconvenience.
That is how Apple increase switching cost for consumer, and they will always come back to Apple to replace their product. Very smart move by Apple.