"The Messenger team's mission is to make Messenger the best place to communicate with all the people and businesses in the world," Facebook head of messaging products Dave Marcus said in an online post.

"I'm happy to report that we've made a good step in that direction, and toward the end of 2015, we crossed the milestone of 800 million people using Messenger every month."

He maintained that while the number was impressive, it was still 'early days' for Messenger.

Improvements to the smartphone messaging application last year included ramping up speed, making it easier to send photos, adding video calling, letting businesses use it for customer service and adding the ability to send money to friends.

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