The number of US advertisers* using mobile display ad campaigns reached 689 in April 2011, up 128% from two years earlier, according to a study by comScore. Campaigns related to mobile content and publishing comprised the plurality of mobile ads, amounting to 50% as of March 2011, followed by ads for consumer discretionary goods (26%), information technology (7%), and financial services (6%).
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http://www.marketingprofs.com/charts/2011/5204/mobile-display-ads-up-128-in-past-two-years?adref=nlt060911
