On Friday, Dropbox filed for one of the most currently anticipated IPOs in the tech world. The file sharing service, which is listing on NASDAQ under the stock ticker DBX, had $1.1 billion in revenue in 2017. The site has 500 million registered users with 100 million of those signing up since the beginning of 2017. Unlike many cloud companies that rely on enterprise sales teams, 90 percent of DropBox's revenue comes from users purchasing a subscription.