Perhaps this seems reasonable if you ignore the inconvenient truth about Apple, Google, Microsoft, and others planning to offer similar services for free
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.