At least, that’s the plan. M only launched today, and we don’t know how well all this will work. As the company expands M to more and more users, it will need more and more trainers. Lebrun expects the number of trainers to grow linearly as the number of users grows exponentially, but the burden could be enormous. Facebook Messenger is used by more than 700 million people. “This is not easy,” Lebrun admits.