It's tough to estimate a fair value for a rapidly growing, barely profitable company like Amazon.com (AMZN -1.14%). With little current profit and most cash flow reinvested in growth, a traditional discounted cash-flow analysis will likely significantly undervalue its true worth.

One way to get an idea is to look at the best-in-class companies with business models similar to what Amazon is trying to build and ask the question, "What if Amazon could wind up like them?"

In the slideshow below, Amazon is compared to three world-class companies with somewhat similar business lines:

  • Walmart (WMT -0.65%) -- the world's largest mass merchandise retailer. With over $400 billion in revenue and decent-for-the-industry 3.4% net margins, Walmart is the closest brick-and-mortar parallel to Amazon's online retail dominance.
  • Apple (AAPL -0.57%) -- the ubiquitous manufacturer of well-loved, simple-to-use technology devices. Amazon's Kindle family of products aims to be a serious contender with Apple's iPads for portable computing and entertainment devices. Plus, with Kindle, Amazon can control a lot more of the overall electronic-publishing value stream, similar to Apple's iTunes environment.
  • Google (GOOG 0.37%) (GOOGL 0.35%) -- the world-class Internet search and information broker. In some sense, what Amazon knows about you may be more valuable than what Google knows about you. After all, most people go to Amazon with an intent to spend their cold, hard cash on something. Knowing what people want to buy is typically more valuable to marketers than simply knowing what people want to find.

These existing strengths are added to Amazon's fast current growth trajectory to estimate what the company could be worth -- if it delivers on the market's expectations.