• by Laurie Sullivan  @lauriesullivan, December 11, 2013

comScore is developing multiplatform measurement that will look at search activity across multiple platforms. Some of the data analyzes mobile search.

Mike Hurt, executive vice president for the data firm, released new qSearch data Wednesday at the MediaPost Search Insider Summit.

One in four U.S. core Web searches occur on mobile devices in the United States, per Hurt. The opportunity continues to expand.

Although three-quarters of searches occur on PCs, more than 100 million consumers ages 13 and older do not use a smartphone.

New comScore data also looks at share by operating system. While Android leads in OS share -- Android at 55.1%, Apple at 42.0 and other at 2.9% - -iOS outperforms for search. When it comes to smartphones, Android takes 52.2%, Apple is at 40.6%, and other is at .1%.

Product Listing Ads (PLAs) also continue to move to mobile, a trend that should support mobile commerce. Today, most retail transactions take place offline, but are influenced by mobile devices. In the first half of the year, mcommerce rose 28% year-on-year, per comScore. Most of the spending on smartphones occurs in apps, about 78% in June 2013, and the remainder on mobile browsers.