800m Facebook users use 'translate' each month

"Machine learning is accomplishing Facebook’s mission of connecting the world across language barriers. Facebook is now serving 2 billion text translations per day. Facebook can translate across 40 languages in 1,800 directions, like French to English. And 800 million users, almost half of all Facebook users, see translations each month.
That’s all based on Facebook’s own machine learning translation system. In 2011 it started working with Microsoft Bing to power translations, but has since bene working to transition to its own system. In December 2015, Facebook finally completed the shift, and now exclusively uses its own translation tech."

Source:  Techcrunch, 23rd May 2016