My dueling partner, Alyce Lomax, framed Amazon.com's (NASDAQ:AMZN) problems perfectly when she mentioned the company's fondness for using low margins to drive sales. Margins are a key component of profit. Without sustained profit, there's nothing to support the company's shares anywhere near their current levels.

The problem is even worse than it appears. Consumers are interested in the best total package, considering price, service, selection, and time between purchase and enjoyment. Without local service and the opportunity for immediate gratification, Amazon must overdeliver on price and selection to remain competitive. With operating margins already at a razor-thin 4.37%, even a 1% reduction in the customer price of a product would knock a gigantic chunk out of profits.

The stock may be down, but it's still not cheap. Things can still get worse.

Think you're done with the Duel? You're not! Go back and read the other three arguments, and then vote for a winner.

At the time of publication, Fool contributor Chuck Saletta had no direct ownership stake in Amazon.com, a Motley Fool Stock Advisor selection. The Fool has a disclosure policy .