Search’s share of U.S. digital advertising revenue has been slowly shrinking over the past few years (it fell below 50% for the first time in 2016). In 2018, search accounted for 45.1% of digital ad revenues, down from 46% in 2017, according to the Interactive Advertising Bureau’s (IAB) annual report on internet advertising.
Search spend growth still accelerated. Search revenue totaled $48.4 billion in 2018, an increase of 19.2% from 2017. That’s a slightly higher growth rate from the previous year. In 2017, search ad revenues increased by 18% from 2016 to $40.6 billion.
Digital video and banner advertising grew faster rates than search last year at 37.2% and 21.9% respectively.
Desktop search share flat, mobile down. On desktop, search retained 48% share of digital ad revenues in 2018. Most formats are showing flat or slight revenue declines on desktop.
Overall, mobile accounted for 65% of digital ad revenues last year, up from 56.7% in 2017. Mobile search revenue grew 37% year over year, but its share of mobile revenue dipped.
Video chipping away at search share. Search’s share on mobile fell from 44% in 2017 to 43% in 2018 as video’s share of mobile revenues increased from 12% in 2017 to 15% in 2018. Mobile video revenues grew by 65.2% year-over-year, and banner and other digital ad formats also saw mobile share declines.
Why we should care. While its share has been shrinking a percentage point or so each year for the past few years, search continues to hold the largest piece of the overall digital ad pie in the U.S. Mobile continues to be the growth driver across all formats, including search. It’s not surprising we’re seeing Google and Microsoft continuing to push search beyond keyword targeting and continue to introduce new formats, targeting and inventory mechanisms.
Overall, U.S. digital ad revenues topped $100 billion for the first time in 2018.