Three years after Facebook's rocky IPO, the company has totally reinvented its business. The stock has more than doubled, and for good reason. It's gone from virtually no mobile revenue to $2.4 billion in that category in the first quarter of this year, 73 percent of its total. It's expanded Facebook's core user base more than 60 percent; more people use Facebook on their mobile devices every single day, than used the service on mobile AND desktop when it went public. And, perhaps most notably, it's expanded from just one service to a portfolio of popular apps.
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. And these two communication apps are sure to become more appealing as they roll out voice calling, taking on the mobile carriers.
Read More Facebook user growth crushes estimates
As the virtual reality company launches its inaugural headset in the first quarter of next year, investors will be watching to see how quickly Facebook's $2 billion acquisition of the company pays off. Oculus' success hinges not just on how many headsets it sells, but also how successfully it lures developers to its platform, rather than rivals like Sony's Morpheus. Another question: Other than video games, what different kinds of experiences, such as entertainment content and communication tools, can developers build on the platform?
Facebook has grown ad revenue so quickly, there's pressure to keep it up. Looking beyond app-install ads, there are a couple of new products that could be key, perhaps most importantly, video ads. There's also the "instant articles"—the company's just-launched system of embedding other publisher's articles on the site, along with ads. And then there's an ad exchange, to enable Facebook to automate the sales process of other publishers' ads.
Read More Facebook enters the minimum wage fight
With 1.44 billion monthly active users, there's no question that Facebook's growth will have to continue to slow, simply because the company has such massive penetration. Mark Zuckerberg has laid out his vision for expanding Internet access to the rest of the world, with drones and satellites, among other things. The success of Internet.org in spreading access may have long-term implications on the potential market for Facebook.