Online storage start-up Dropbox announced it has raised $250 million for its expansion, one of the largest fundraising rounds in Silicon Valley this year.
The investment values the company at a reported $4 billion. Its founders Drew Houston and Arash Ferdowski, Massachusetts Institute of Technology alumni, earlier this year were named to Inc.'s 2011 30 Coolest Entrepreneurs Under 30 list.
The San Francisco start-up, founded in 2007, lets users access photos, documents and other files from almost anything that can be connected to the Internet. Its growth has been explosive: It currently has some 45 million users, nearly double of the 25 million it had in April. People in 175 countries save 1 billion files every three days using the service, the company said.
The round was led by Index Ventures, with other investors including Goldman Sachs, Benchmark Capital, Greylock Partners, Institutional Venture Partners, RIT Capital Partners and Valiant Capital Partners. Two previous investors, Sequoia Capital and Accel Partners, also participated.
Dropbox said it would use the money, $257.2 million, to be exact, for acquisitions, partnerships and growth.
"Our goal has always been to build a service that hundreds of millions of people would love and trust," Houston, 28, said in a statement. "We're thrilled to have world-class investors joining forces with us."
Dropbox's last fundraising effort was just $7.2 million in 2008. Dropbox turned down a multimillion dollar acquisition offer from Apple in 2009, Forbes reported in a recent article. Rumors have put the offer as high as $800 million.
Dropbox's current projects include getting its products installed on all manner of devices: phones, printers, scanners, cameras and more. In September, the company announced it had partnered with HTC, and that new HTC Android phone users using the Sense 3.5 interface would get 5GB of free cloud storage. (Normally Dropbox offers 2GB free.) Windows Phone 7 devices already have Microsoft's competing Skydrive service on their operating system, which offers 25 GB of free storage.