Facebook, Google, Amazon, Apple, which one does not belong?

Soon, Facebook will have its IPO (initial public offering) and its stock will "go public" so everyone can buy a piece of the social media juggernaut. Some may put it in the same category as Google, Amazon and Apple, but I would not. Facebook will not have the staying power of those companies. In attempts to take over much of the internet, many sites now want you to sign in via Facebook. It is hard to put a valuation number on Facebook, just like other social media companies since they usually lose steam over time and fade away (remember My Space?) It seems like the best time for Facebook to have gone public would have been about 5 years ago, when it was relatively unknown outside of a few college campuses. At that point, its meteoric growth was still ahead of it. This article has some good points about Facebook's valuation: http://www.thestreet.com/story/11510355/1/facebook-has-no-business-being-compared-to-apple-google-and-amazon.html