Insights from Opera Mediaworks | The State of Mobile Advertising Q2 - 2013: "iOS continues as the top OS in monetization and regains lead in mobile phone impression volume
Overall, iOS is the clear market leader in both impression volume and revenue generation, capturing nearly 44% of all ad impressions and almost half of all revenue.
However, when comparing mobile phones using iOS and Android the two OS are in a virtual tie for share of ad impressions, with just over 30% each. Late last year, Android inched ahead of iPhone with a slight lead (31% vs. 29%), but iPhone has been inching back and, within one percentage point ever since.
The iPhone still triumphs in terms of monetization, however, with 36.4% of revenue vs. Android’s 27.8%. And while in Q1 Android tablets began appearing in our data set, their market share is still almost imperceptible. Traffic share (mobile phone OS)"