Despite its valuation, the e-commerce behemoth generates only a fraction of the retail sales that the other 21 companies do, combined. In fact, Walmart by itself sold almost $500 billion in goods worldwide in 2017, more than three times as much as Amazon, according to Kantor Consulting.
Consumers can buy goods from third parties on Amazon, and the company charges a fee, generating less revenue than it would if it sold the product itself. Amazon also has other revenue streams beyond retail, including its web services.
Analysts say Amazon is expensive based on its operating profit margins, but investors are valuing the company based on its future growth potential.