Note: The Experian Hitwise 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 Experian Hitwise sample of 10 million US internet users. Experian Hitwise measures more than 1 million unique websites on a daily basis, including sub-domains of larger websites. Experian 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.
The Retail industry is still the top-spender, but its share of total spend has fallen over the past 5 years.