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If Wall Street’s measure of a company’s promise is its market value, then Facebook Inc.’s (NYSE: FB) extraordinary earnings have put it solidly on the list of the 25 most valuable companies in the United States based on market capitalization. As a matter of fact, it has moved next to public corporations such as Verizon Communications Inc. (NYSE: VZ), Citigroup Inc. (NYSE: C) and Intel Corp. (NASDAQ: INTC). After a post-earnings run-up, Facebook’s market cap has reached almost $150 billion.

To put the Facebook market cap in perspective, its annual revenue run rate is $15 billion, adjusted for current growth. Measure that against Intel’s at $53 billion and Verizon’s at $115 billion. The numbers from these two companies show roughly how high investors expect Facebook’s revenue to grow. Granted, Intel’s best years may be behind it because of trouble in the PC market. However, it is still the leader in its sector, and it has a chance to move into the sale of chips for smartphones. Verizon’s growth may have slowed considerably because of the glut of cellphone subscriptions in the United States, but it may make more money on smartphone data plans and fiber to the home TV and broadband.

Facebook’s high market cap may not justify the hurdles it faces, as Apple Inc.’s (NASDAQ: AAPL) did not two years ago when its stock traded at $700, compared to about $500 now. Competition hit Apple harder than many investors expected. Facebook has high risk of a similar fate.

Facebook’s challenge remains that it has not broken into what many analysts believe is the core of ad revenue growth — the search ads that are controlled by Google Inc. (NASDAQ: GOOG), or the video ad market, which is small but growing and highly profitable. What Facebook has done, which was largely unexpected, is drive its mobile business higher without a terrible erosion of ad rates suffered by other Internet sites that have migrated from PCs to tablets and smartphones. Facebook also has been able to mine data about its users at an extraordinary level to help advertisers precisely reach their intended customers.

However, Facebook’s strength may turn out to be its weakness. It has provided its rivals with a road map for sophisticated targeting of online visitors. It does not have a corner on that technology. Its ability to create value from mobile users may be difficult to mimic, but other huge Web properties will make huge investments to try.

Facebook’s ratio of market cap to sales is 20 times. As investors look the future, they can consider that for Apple the number is less than three times. Facebook’s revenue growth has a long, long way to grow to justify its market value.