CNBC: Three years after Facebook’s rocky IPO, the company has totally reinvented its business. So what’s on the agenda for the next three years? WhatsApp has 800 million monthly active users, Facebook Messenger has 600 million and Instagram has more than 300 million. While Instagram works to slowly roll out ads — careful not to alienate users — the question now is how WhatsApp and Messenger can similarly make money from their devoted users.