• by Steve Smith  @popeyesm, December 11, 2012

Google Android may be in more people’s pockets by a wide margin worldwide, but Apple's iPhone and iOS ecosystem continue to rule the mobile ad economy, says Opera Software in its year-end report. In measuring over 40 billion monthly impressions to more than 10,000 mobile sites over the last year, Opera found that 44.4% of ad impressions still were going to iOS devices, compared to 29% to Android. The perennial battle between the two OSes over the effects of fragmentation continued to favor Apple. Within months of the iOS 6 upgrade release, 65% of Apple smartphones and tablets are running on the new software.

Far and away the leader in mobile monetization this year has been the iPad, which Opera reports earning an eCPM of $3.60 consistently.

And in another head-to-head match-up, this time between the iPhone 5 and Samsung’s strong contender the Galaxy S III, Apple maintains a lead. Just four months after the iPhone 5 launch, it is already responsible for 16.1% of iPhone device traffic, while the Samsung flagship phone gets 8% of Android traffic.

Among content categories, music and video were the big winners in 2012. Opera cited high growth at companies like Pandora, Slacker Radio and Shazam, helping the music and video category generate 23.8% of all mobile ad impressions and about 15% of revenue. Sports was also on a fast track, growing from 4% of ad revenue at the beginning of the year to 14% by year’s end. Opera attributes the growth both to traffic increases and the use of more high value rich media units.

Opera provides an ad platform to many of the largest mobile publishers, including CBS, MLB.com, News Corp, Bloomberg, Pandora and Shazam.