Earlier this week Facebook acquired the mobile data analytics company Onavo. The original spin was that this was a great fit with Internet.org, given that Onavo’s apps are focused on monitoring data usage and maximizing the amount of data you get per kilobyte. Onavo said as much in their blog post announcing the acquisition:

As you know, Facebook and other mobile technology leaders recently launched Internet.org, formalizing Facebook’s commitment to improving access to the internet for the next 5 billion people — this is a challenge we’re also passionate about. We’re excited to join their team, and hope to play a critical role in reaching one of Internet.org’s most significant goals – using data more efficiently, so that more people around the world can connect and share.

That’s nice, and makes for great PR, but I’d bet Facebook is much more interested in Onavo’s analytics business. From AllThingsD:

The added value of those apps is that they beget Onavo’s analytics biz, which gives app makers the ability to gauge how their apps fare on the open market, as well as giving more insight into how people actually use the apps after they’ve downloaded them. It’s certainly valuable data for any company to own and mine.

Indeed it is, particularly for Facebook.

In some respects, Facebook has the opposite problem as Twitter, and the acquisition of Onavo – and Parse, a few months back – are thus mirror images of Twitter’s MoPub acquisition. From a stratechery article I wrote about Twitter and MoPub:

I think it’s very likely MoPub is Twitter’s AdSense:

• Twitter has a great signal about its users: whom I follow is a great approximation for what I’m interested in. That’s even more valuable than whom I know
• Twitter is not a great platform for any sort of display advertising; the targeting would have to be much more precise than what is possible with current technology for users to tolerate anything more than promoted tweets

MoPub solves this riddle; Twitter can serve up highly targeted ads everywhere but Twitter proper. It’s a great acquisition.

Facebook, on the other hand, has potentially the best platform for display advertising – their mobile apps. As I wrote in Mobile Makes Facebook Just an App; That’s Great News:

Brand advertising, especially, is all about visuals and video (launching soon!), but no one has been able to make brand advertising work as well on the web as it does on TV or print. There is simply too much to see on the screen at any given time.

This is the exact opposite experience of a mobile app. Brand advertising on Facebook’s app shares the screen with no one. Thanks to the constraints of mobile, Facebook may be cracking the display and brand advertising nut that has frustrated online advertisers for years.

Still, though, for all the information we give Facebook, they know less about our interests and wants than Twitter or Google, and the quality of signal is just as important as the platform for displaying ads. It makes sense for Facebook to build out an analytics platform that gathers signal throughout the mobile ecosystem, making Facebook’s immersive mobile advertising that much more effective.