WhatsApp just hit a major milestone that seemed unimaginable even for Facebook a few years ago. The messaging service has revealed that it now has over 2 billion users, a figure that its parent company reached back in 2017. It didn't explain just how it reached that user count, but it's not hard to see why. WhatsApp is a staple of mobile communication in many parts of the world, and in some cases plays an important role in shopping, political campaigning and other aspects of daily life. There are few other major rivals, and its sibling Facebook Messenger is one of them.