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The digital research website is also predicting that the top four companies in the category — including Google and AOL — will have more than half the market by year-end.
Google is a relative newcomer to display ads, but it dominates search-related advertising with its AdWords service, which will have three-fourths of the U.S. market in 2011, eMarketer predicts.
Google’s vast storehouses of data on consumer behavior, collected through its analysis of billions of searches, allow it to target display ads more effectively than some of its competitors.
All of these big players have automated ad-delivery systems that reduce the need for salespeople and cut costs to advertisers in terms of cost per impression, cost per click on an ad or cost per transaction. It is tough for smaller advertising networks to compete.