For every business, there is a core value proposition that sits at the heart of everything the business does.
This value proposition drives the product, the brand, the culture, the strategy and everything in between. As a business, if you're weak on your value proposition, everything else will be weak.
You need to know what drives your customers, what drives your team and what drives you, as this is what will drive your core value.
The best way to do this is by asking the right questions to understand the experiences, beliefs and reality states of the people that are a part of your business. That's yourself, your customers, your team, and anyone else who plays a material role. What is the one thing that drives or will drive your success?
For Amazon, this one thing is customer service. Every decision that they make is driven by the underlying goal of improving customer service.