6. Dropbox

6. Dropbox

Estimated Value: $3.5 billion
Last Year's Rank/Valuation: #6 / $4 billion
Business: Dropbox is a free service that lets you bring your photos, docs, and videos anywhere and share them easily.
Location: San Francisco, California
More Info: About Dropbox
CEO: Drew Houston
Investors: Dropbox closed a massive $250M round led by Index Ventures with participation from Benchmark Capital, Goldman Sachs, Greylock Partners, and others in October 2011. It received seed money from Y Combinator and, in fall 2008, Sequoia Capital led a $7.2M Series A with Accel Partners.
Analysis: Dropbox has about 50 million users and it generated an estimated $240 million last year. It was reportedly profitable at the time of the valuation even though most of its users don't pay for the service. For those who do pay, the fees start at $10 for 50 gigabytes.
While he didn't reveal Dropbox's current valuation, Y Combinator's Paul Graham mentioned recently that Airbnb and Dropbox are worth about $7.5 billion combined.
Still, at a $4 billion valuation, Dropbox is worth as much as companies that generate a billion in revenue, and competitors are coming after the storage space quickly, from Apple to Box. Times aren't as good as they were last year, so we estimate Dropbox's valuation at a more modest $3.5 billion.