I have a simple mantra: If it's not food, warmth or sleep, it's not worth buying. Therefore it begets the question: HOW DO WE SELL PRODUCTS? Many institutions have come up with many different solutions, each innovative than the last but what's common between them is that they are all aware of the vital part a good and understandable system design plays on overall user experience, due to which the user is inclined to purchase the product. Some illustrious examples include Google's simple yet effective homepage or Apple's renowned Eco-system.
For me, I like to think about how the user thinks; when I hold a product I do not use the product I analyze the thought process behind the design. That for me, being in the shoes of a user, is what drives innovation.