TechCrunch has the story, which cites Cowen analyst Jim Friedland, who estimates that Google is raking in $7 per mobile device per year, both running Android and Apple’s iOS platform, since Google ads reach other platforms through search and web ads as well. That’s going to help Google’s mobile ad revenues jump significantly, Friedland says – going from $2.5 billion in 2011 to his estimated $5.8 billion this year.

The biggest driver for that spike is the greater proliferation of mobile devices around the world. This benefits Google as much as any other company by allowing Google to advertise. Smartphone activations in 2012 are expected to rise to 914 million worldwide from 508 million last year. The chunk of Google’s ad revenue that comes straight from mobile ads (as opposed to web ads) is expected to pick up significantly as well, rising from an estimated 3 percent in 2010 to 7 percent in 2011, and doubling again by 2012 to 14 percent, Friedland says. He expects it to increase to a $20 billion revenue stream by 2016, accounting for an estimated 23 percent of Google’s ad business. All those figures are estimates because Google doesn’t release mobile ad revenues regularly.

Whether Google’s mobile ad revenue really could get up above $5 billion depends on smartphone sales for 2012. Last year, Google said during an earnings call that its total display ad business, including mobile, was hitting around a $5 billion annual run-rate. This suggests a really big increase to get just the mobile side up that high. Then again, if smartphone sales really do hit nearly a billion worldwide, that increase in Google’s ad revenue could definitely happen.

More big advertising figures from Google are a good thing when it comes to smartphones, if only because it continues to support the proliferation and refinement of Android and Google’s other mobile offerings. Even Google apps spread to other platforms like iOS are made with an eye toward advertising revenue.

Given the pace at which the smartphone and mobile markets have been growing just in the last few years and months, it seems entirely possible we could be seeing 914 million smartphones worldwide by the end of 2012. It’ll be interesting to look back in 11 months and see how the landscape changes, with more mobile devices, an increasing market and of course, more advertising.