That would amount to roughly $5 billion in revenues from tablet ads alone for the year. Overall, Google is expected to earn $9.9 billion in total mobile revenues in 2013, up from an estimated $5.8 billion in 2012.
The strong performance of tablet ads, coupled with a surge in user adoption, is driving the rise in ad investment, according to the report.
Below, additional findings the report titled "Mobile Search Advertising Around the Globe: How Smartphones and Tablets Are Changing Paid Search," by Marin Software.
Effectiveness of Ads
On average, the conversion rate for search ads served via tablet was 3.3% at the end of 2012, compared with 3.9% for desktop and 2.8% for smartphone:
Meanwhile, the effectiveness of Google's tablet search ads are rising. Conversion rates on search clicks via tablet devices increased 31% from January to December 2012 , compared with a 9% rise for smartphones and 7% for computers.