Two years later, the integration of Google's $750 million acquisition of mobile ad network AdMob into the mothership may finally be complete.

Google is set to announce that AdMob's mobile display ads, which appear in more than 300,000 apps on phones, will now be available in the engine that powers much of Google's $37 billion in annual ad revenue: AdWords. That tool is what Jason Spero, head of global mobile sales and strategy at Google, calls the "nuclear power plant at the core" of the company.

The integration makes it more simple to spend money on mobile ads, since now they can be bought and managed in the same place as other ad efforts, like search and display. Connecting those pipes means the majority of Google's advertisers will have access to a medium that's suffered from smartphone usage far outpacing the ability for advertisers to spend on the device.