Note: Nielsen/NetRatings AdRelevance service uses a proprietary methodology for estimating online advertising expenditures and takes into account only image-based technologies and advertising sold per CPM. Above data does not reflect house advertising activity, strategic partnerships between publishers and advertisers, or text units, paid search, sponsorships, email, units contained within applications (e.g., messengers and pre-rolls) or performance-based advertising.

US Digital Ad Spend Grew Faster Last Year Than At Any Point in the Previous 15 Years
For all but the largest 25 publishers, the actual amount of ad spend in play was a little over $28 billion.