There are three types of Dropbox accounts, Free, Pro, and Teams, which is offered toward businesses. Dropbox allows users to store 2 GB of data for free, all the way up to 18 GB if you refer other users. The Pro plan starts at $9.99 per month for 100 GB worth of storage, and increases from there. The San Francisco-based Dropbox has been consumer-oriented in its focus, but the company is increasingly putting more attention toward businesses, where it believes additional growth will come from. The company is reported to have generated $240 million in revenue in 2011, though nothing is known about 2012 revenue. According to the company's Web site, Dropbox has more 100 million people across the globe using its products, so it already has a wide user base. Dropbox became so popular so fast that then Apple ( AAPL) CEO Steve Jobs approached Houston about buying the company in 2009 with a "nine-figure offer," but was ultimately rebuffed.