Is Dropbox Really The World's 5th Most Valuable Startup?

Dropbox, the online file sync and sharing service, was recently named 5th in a list of the The World's Most Valuable Startups by Business Insider. To put that in context, the only 4 companies ranked above Dropbox were (in order of valuation): Facebook, Zynga, Groupon and Twitter. Dropbox was listed above the likes of Wikipedia, Craigslist, Hulu and Tumblr. Business Insider estimated the value of Dropbox at $4 billion, based on its latest funding round at the end of August.
Is Dropbox Really The World's 5th Most Valuable Startup?

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