WhatsApp now has 800-million monthly active users, continuing a pace of growth that may put the mobile messaging app on track to hit 1-billion users later this year.

In a Facebook post Friday, WhatsApp CEO Jan Koum announced that the Facebook-owned service now has 800 million active users every month. That’s a lot of chatter. The app, which Facebook bought in 2014 for $22bn, has added 100-million active monthly users roughly every four months since August, when it had 600-million users.

In January, WhatsApp announced that it reached 700-million.

WhatsApp has more users than any other similar app, including Facebook Messenger, and has become an alternative to text messaging for many people around the world. WhatsApp recently launched a feature allowing users to take calls through the app.

WhatsApp Messenger lets you send text messages to other users of the app for free. The app sends messages over the Internet, bypassing a phone carrier’s text messaging charges. The app is available on just about every mobile platform, including iOS, Android, Windows Phone and BlackBerry devices. WhatsApp has also rolled outa voice calling feature, firing a shot across the bow of services like Skype and Viber.

It took Facebook roughly eight years to reach the 1-billion mark. Facebook now boasts about 1.4-billion monthly users, while its Messenger has about 600-million.

Founder and CEO Mark Zuckerberg has previously said he expects WhatsApp to contribute to the company’s bottom line, but not until it reaches roughly a billion users.

In January, he reiterated that he expects WhatsApp to be an important contributor to Facebook’s business.

“What I’d say around messaging is we’re pretty early in that cycle,” Mr Zuckerberg said during the company’s fourth-quarter earnings call.

“We are about where Facebook was in around 2006 or 2007, where, at that point, Facebook is really just a consumer product. There were no businesses in the ecosystem.”