2. Dropbox is worth $10 billion.

Cloud storage startup Dropbox, which has more than 200 million users, was valued at $10 billion as of December 2013.

To date, Dropbox has raised $507 million from Accel Partners, Benchmark Capital, BlackRock Private Equity Partners, Glynn Capital Management, Goldman Sachs Group, Greylock Ventures, Index Ventures, Institutional Venture Partners, RIT Capital Partners, Sequoia Capital, Valiant Capital Partners, and Y Combinator.