Facebook's WhatsApp hits another major milestone

WhatsApp, the messaging app that Facebook bought for about $19 billion in 2014, has 900 million monthly active users, according to its founder Jan Koum (who posted about the milestone on Facebook, naturally).

That's up from 800 million MAUs in April, and 700 million at the start of the year.

At that rate, WhatsApp could conceivably hit the magic 1 billion landmark before the end of the year.

With WhatsApp and Messenger (which spiked to 700 million MAUs in June), Facebook controls the two biggest messaging apps in the world. WeChat, owned by the gigantic Chinese company Tencent, earns third place at 600 million MAUs. After that, there's a significant gap in size: Viber, acquired by Japanese company Rakuten in 2014, has upwards of 236 million monthly active users, and Line, another Japanese app, has 205 million.

But neither Messenger nor WhatsApp has adopted the money-making efforts of their competitors. Line reported $214 million in revenue in its first quarter earnings thanks to sticker sales, game purchases, and promoted messages from businesses and celebrities.

Facebook doesn't break-out revenue for Messenger or WhatsApp, but on its own earnings call, CEO Mark Zuckerberg asked investors for their patience regarding their monetization.

He said that right now the company is focused on making Messenger and WhatsApp a natural place for people to communicate with busineses. Then Facebook will find ways to monetize those relationships.

"The long-term bet is that by enabling people to have good organic interactions with businesses, that will end up being a massive multiplier on the value of the monetization down the road, when we really work on that, and really focus on that in a bigger way," Zuckerberg said. "So we ask for some patience on this to do this correctly."