On launch, one of the biggest hurdles that Amazon encountered in its business was the lack of immediacy — the time between desire and delivery led to lost sales.
A core part of its business strategy since then can be seen as trying to eliminate this friction, erasing that lag between want and have, making it almost instant.
Where a good can be transferred into something digital, Amazon has invested to do that. Most successfully, you have the Kindle and e-books. Amazon also delivers music and movies digitally, and is trying, with only mixed success so far, to have the Kindle Fire be the hub for that.
For those goods that will be physical, the Amazon logistics, primarily in the form of Amazon Prime, have made two-day delivery the expectation. Increasingly, in some markets like New York, sometimes one has the mind-bending pleasure of getting goods on the same day without having paid extra, and Amazon is building more local warehouses around the country to make this an even more regular occurrence for customers.
Amazon has the edge in prices, and in customer experience. The closer it gets to achieving its instant strategy, it gets almost unstoppable, having eliminated one of the primary remaining reasons to walk into a brick and mortar retailer.