Note:Â TheÂ ExperianÂ Marketing ServicesÂ data featured is based on US market share of visits as defined by the IAB, which is the percentage of online traffic to the domain or category, from the Hitwise sample of 5 million US internet users. Hitwise measures more than 1 million unique websites on a daily basis, including sub-domains of larger websites. Hitwise categorizes websites into industries on the basis of subject matter and content, as well as market orientation and competitive context. The market share of visits percentage does not include traffic for all sub-domains of certain websites that could be reported on separately.
For all but the largest 25 publishers, the actual amount of ad spend in play was a little over $28 billion.