According to the Interactive Advertising Bureau's Internet Advertising Revenue Report, which is compiled using information supplied by companies selling advertisements on the internet, total digital ad revenues increased 16% during 2014 to reach a new high of $49.5bn.
Mobile advertising advanced 76% to hit $12.5bn over the same period, raising its share of the total from 17% to 25% in just 12 months.
"Marketers clearly recognise that consumers are leading mobile-first lives and are investing their ad dollars accordingly," said Randall Rothenberg, President and CEO, IAB.
Social media advertising also saw stellar returns, bringing in $7bn in 2014, up 57% on the previous year. David Silverman, partner at PwC US, which prepared the report, noted that social was "a significant mobile activity" and was "driving growth in advertising revenue as consumers spend more time connected".
Digital video grew more than three times as fast as display, of which it is a component part. It was up 17% to $3.3bn, compared with 5% uplift seen in the wider display market which was valued at $13.5bn.
Banner ads increased just over 1% to $8.0bn while rich media registered a 6% uptick to reach $1.4bn. Overall, display's share of the digital market slipped from 30% to 27%.
Search continued to advance at a slow pace, rising 3% to $19bn. It remains the largest digital format but its share of the market fell from 43% to 38%.
Retail advertisers continued to represent the largest category of internet ad spending, responsible for 21% in 2014, followed by financial services and automotive which accounted for 13% and 12% respectively, figures which were the same as in 2013.
Warc's latest International Ad Forecast (December 2014) had estimated a 15.9% rise in US digital adspend in 2014, 0.1pp below the confirmed total. The forecast expects a further rise in US digital adspend of 13.6% this year.
Data sourced from IAB: additional content by Warc staff