Facebook's stock slumped to $17.55 last week and even Monday it was trading at just $18.75. That's nearly 50 percent below its IPO price of $38. But it's still no bargain. At its valuation as of September 4, Facebook's price to earnings (P/E) ratio was 62.5. Compared to Google's 20.3 and Apple's 15.6, a P/E ration of 62.5 doesn't look reasonable. The P/E ratios of Amazon and LinkedIn don't look very sane either at the moment, but Amazon is investing heavily in future growth and should soon bring in better numbers. LinkedIn is actually growing more than twice as quickly as Facebook and it is focusing on three revenue streams, while Facebook still depends on advertising to make money.
