According to the new figures, revenues for the sector reached $8.4bn during the three month period, 15% more than the $7.3bn recorded during January-March 2011 and the highest first quarter total since the report began in 1996.
The report chimes with latest Warc data contained in the International Ad Forecast, which suggested that US online adspend will rise by +10.5% during 2012.
Commenting on the latest figures, IAB president Randall Rothenberg said that marketers had reflected a broad shift in consumers' media habits by allocating a greater proportion of their budgets to online.
"Marketers and agencies are clearly - and wisely - investing dollars to reach digitally connected consumers," he said.
David Silverman, a partner at PwC US, added: "A 15 percent increase over the comparable period in 2011 is a solid affirmation the internet is delivering on its promise to attract consumers and the advertising dollars that follow."
Data sourced from IAB; additional content by Warc staff