Facebook CEO Mark Zuckerberg revealed during an earnings call that 400 million people are now using Messenger daily for audio and video calls. That figure is up from 300 million in September 2016. The introduction of multi-screen group video chats in December likely helped to boost usage rates.

Video calling in Facebook could have an impact on other apps like Skype and Google’s Duo. Facebook has access to so many users that it’s become more difficult to compete against its platform.

As Zuckerberg has made clear, the company’s video push goes beyond calling. He says Facebook is currently investing in longer-form video content for the main social network.