ClickZ: The study sought to find out if mobile ad extensions made a difference in click-through rates on mobile devices. Read on to learn the results.
Bing conducted a simple, but telling eye-tracking study with search ads and mobile ad extensions. With huge mobile growth (Bing Ads is seeing 122 percent year-over-year growth in mobile ad clicks), this has never been more relevant. Bing Ads did an eye-tracking study and found that, the more extensions your mobile ad has, the more attention it gets.
http://www.clickz.com/clickz/column/2342497/eye-tracking-heat-map-study-for-mobile-search