7. Music-streaming company Spotify is valued at $4 billion.

When Spotify raised $250 million in new financing last November, the music company's valuation reached $4 billion.

To date, Spotify has raised $521 million from investors like Accel Partners, Coca-Cola, Creandum, Digital Sky Technologies, Fidelity Investments, Founders Fund, Goldman Sachs Group, Kleiner Perkins Caufield & Byers, Li Ka Shing Foundation, Northzone Ventures, TCMI, and Wellington Partners.