Every year in my annual letter, I try to share insight into what makes Amazon tick. At the highest level, we're aiming to be Earth's most customer-centric company, making customers' lives better and easier every day. This is not easy to do in general, let alone year after year.

We've had this long-held philosophy at Amazon about two-way and one-way door decisions. A two-way door decision is one where if you get the decision wrong, you can walk back through that door, revert to where you were, and there are few ramifications. A one-way door decision is one where it's quite difficult to walk back through that door if you get the decision wrong. But both of these constructs assume the door is unlocked. A lot of invention is about trying to open doors that have historically seemed bolted shut.

Over the past 30 years, we've found one of the most important keys to unlock these doors has been a simple question: "Why?"

"Why does this customer experience have to be this way?" "Why can't it be better?" "What are the constraints—why must we accept them?" "Why can't we invent around that?"

Amazon is a Why company. We ask why, and why not, constantly. It helps us deconstruct problems, get to root causes, understand blockers, and unlock doors that might have previously seemed impenetrable. Amazon has an unusually high quotient of this WhyQ, and it frames the way we think about everything that we do.

Every one of these Whys have led to significant invention, and every one of them have made customers' lives better and easier. Some of these seem obvious now. But at the time, these were provocative questions that required curiosity, risk-taking, experimentation, and persistence to make these into success stories.