How brands could benefit from Facebook Messenger joining the one billion users club

Facebook Messenger has this week joined the illustrious billion users club. Given that Facebook’s 1.65 billion users are only ever about one click away from sending a message, this perhaps shouldn't be a surprise. However, it's still a weighty number for a platform that Facebook is increasingly building out in its own right.
It celebrated the occasion by rolling out an Easter Egg that floods the screens with balloons any time the balloon emoji is used. On the face of it that's a small gimm