In some respects, Amazon is a hard company to categorize. When it opened for business a little over two decades ago it was an online seller of books. Since then Amazon has, among other things, expanded its e-commerce platform to include a broad spectrum of consumer products; launched a line of electronic readers, tablets and other devices; emerged as a leader in cloud computing; produced original films and video programming; and now, with the acquisition of Whole Foods, entered traditional grocery retailing.

The diversity of those operations makes it difficult to typify the organization. Perhaps the best way to summarize Amazon is to call it an innovation company, one whose hallmark is a commitment to continuous improvement. That view would probably win the endorsement of Amazon founder and chief executive officer Jeff Bezos, whose most recent annual letter to stockholders, which was released in April, stresses the importance of the company adhering to its habit of thinking and acting like the disruptive force it has been since its inception.

Bezos is known for concluding his missives to shareholders with the sentence, “It remains Day 1,” an idea that he first expressed back in 1997. The gist of the latest letter is the imperative to maintain that attitude and fend off the dawn of Day 2, which he characterizes as stasis — “Followed by irrelevance. Followed by excruciating, painful decline. Followed by death. … To be sure, this kind of decline would happen in extreme slow motion. An established company might harvest Day 2 for decades, but the final result would be the same.”

Although not cited by Bezos, the history of A&P, which at one time was a more powerful force in the U.S. market than Walmart is today, and the current struggles of Sears Holdings illustrate the point very well.

The letter goes on to talk about steps that Amazon needs to take to avoid a similar fate: “Here’s a starter pack of essentials for Day 1 defense: customer obsession, a skeptical view of proxies, the eager adoption of external trends, and high-velocity decision making.”

The elaboration of those concepts makes for interesting reading, and, while one may disagree with some of the specifics in Bezos’ argument, it is clear that Amazon is not about to settle for the status quo. The company that has done more than any other in recent years to transform the way people shop for and buy consumer products is continuing to raise the bar for the entire retail industry. Among the innovations in the works are Prime Air delivery drones; the Amazon Go brick-and-mortar store format that eliminates checkout lines; and Alexa, the cloud-based artificial intelligence assistant that works through the Amazon Echo voice-controlled speaker. And, as Bezos notes, much more is happening behind the scenes.

As long as it succeeds in executing against the vision espoused by its founder, Amazon will remain a formidable competitor for the companies that have long dominated mass market retailing. Equally, if not more, important, Amazon’s plan of attack, willingness to take risks and  speed in implementing new ideas raise questions about the effectiveness of more conventional corporate approaches to how decisions are made.

Traditional retailers in the age of Amazon must learn how to  innovate much more quickly than in the past, admittedly a formidable task for companies with hundreds or thousands of brick-and-mortar locations. Failure to do so will hasten the moment they find themselves on Day 2.