Out of the $2.5 billion it made in Q1 this year, $2.27 billion was from advertising and a little over $1.3 billion -- that's around 59 percent -- was from mobile ads alone. That's quite a jump from the 30% it made from mobile ads in the same quarter last year.

That, more than anything, is what is driving the social network to invest heavily in a multi-app strategy. Zuckerberg said on the earnings call that the company plans to give people new apps for sharing different kinds of content with different audiences. The push for Messenger as a standalone app is part of this, and it's also the thinking behind Paper, a Facebook app that offers a more creative and nuanced look at the traditional news feed. In an interview with the New York Times earlier this year, Zuckerberg said "there's a big premium on creating single-purpose first-class experiences," which essentially means unbundling what he calls "the big, blue app."

He reiterated in the call that around a billion people use that big, blue app, so they clearly won't be giving up on it just yet. But he was also excited about the growth of Messenger and Instagram which he says have around 200 million users each (Instagram only had about 30 million users pre-acquisition). He's also very pleased by the early reaction to Paper and expects that to be a good test case for the multi-app strategy going forward. However, the primary goal for all of these apps right now is to focus on gaining more users. Even Whatsapp, which just reported nearly 500 million active users, has room for growth. According to Zuckerberg, he'd like Paper to reach 100 million users before trying to make it sustainable and for the rest to reach around a billion before he worries about monetization.

Still, that's clearly where the company is headed. It's already started displaying ads on Instagram and is moving toward more experimental forms of advertising like autoplay video commercials. There's also rumblings that Facebook plans to reveal a mobile ad network so that those targeted ads can appear in apps that are not its own.

As rivals like Twitter begin to experiment with advertising, it's time for Facebook to focus on those smaller, more focused projects, not just the big, blue one.