Facebook had purchased Whatsapp for $19 billion in late 2014 from co-founders Jan Koum and Brian Acton, and Zuckerberg thanked them in a post on his Facebook page.
He wrote: “One billion people now use WhatsApp. Congrats to Jan, Brian and everyone who helped reach this milestone!
“WhatsApp’s community has more than doubled since joining Facebook. We’ve added the ability for you to call loved ones far away. We’ve dropped the subscription fee and made WhatsApp completely free. Next, we’re going to work to connect more people around the world and make it easier to communicate with businesses.
“There are only a few services that connect more than a billion people. This milestone is an important step towards connecting the entire world.”
