It was a little over 10 years ago that Amazon.com (NASDAQ:AMZN) opened its virtual storefront. The company started off selling books and evolving into other forms of media like DVDs and compact discs. These days it's easier to narrow the list down to what it doesn't sell than what it does. From Segway scooters to iRobot (NASDAQ:IRBT) robotic vacuum cleaners, the Seattle-based company sells it all. It lives up to its claim of offering Earth's Biggest Selection.

The stock has nearly tripled since being recommended to Motley Fool Stock Advisor subscribers a little more than three years ago. That was just as the company was shedding its skin as a money-losing dot-com bellwether and about to embark on its new life as a consistently profitable model for Web-based commerce.

Is Amazon still worth buying? Not all Fools agree. Rick Munarriz believes that the market is underestimating the company's true earnings potential, while Rich Smith feels that investors would be overpaying if they were to scoop up shares of the world's largest e-tailer at this point.

One thing for sure is that Amazon is an online retailer with staying power. As smaller niche players like drugstore.com (NASDAQ:DSCM), Red Envelope (NASDAQ:REDE), and Bluefly (NASDAQ:BFLY) struggle to turn a profit, few will argue that Amazon is going away anytime soon. But is it going up or down in the meantime? That's what this week's Duel is all about.

Duel on!