Facebook announced this week that Facebook Messenger, its standalone messaging client that was first deployed in 2011, hit a new major milestone. The service is now used by 500 million people around the globe. That would be a pretty huge figure if not for one major problem: Facebook forced its users to download Facebook Messenger instead of using the now defunct in-app version. It's still impressive, however, considering that WhatsApp, which Facebook paid about $19 billion to acquire, had 600 million monthly active users back in August.

"This is an exciting milestone but with a half billion people relying on Messenger to communicate and connect, it is also a reminder that there is so much left for us to do," Facebook's director of product management Peter Martinazzi said on Monday, highlighting some of the services features, including group chat, support for stickers, photos and videos, and even free calls. He also noted that Facebook Messenger is updated every two weeks to keep it fresh and exciting for users.

The social network is still working to add even more value, however, and a report in October from the Guardian suggested that the firm plans to enable a new mobile payment service for Facebook Messenger users, which would help it monetize those millions of users. Separately, Facebook is also adding new features to WhatsApp, including VoIP calling support. With two major messaging platforms under its portfolio, Facebook has quickly become the king of chat.