In a bright sign for digital media like podcasting, the Interactive Advertising Bureau (IAB) reports U.S. advertisers spent 18% more on digital advertising resulting in the industry’s strongest Q1 on record. Total ad spending hit $28.4 billion. That’s $4.5 billion compared to the first quarter total a year ago. The IAB didn’t release any specific data on how each of the digital segments including podcasting performed, but with such strong growth numbers and expanding listeners it’s likely podcasting ad revenue experienced similar growth.

“The continued growth of digital ad spend is a reflection of its ability to help brands and publishers reach consumers and build meaningful one-to-one relationships,” said Sue Hogan, Senior Vice President of Research and Measurement at the IAB. She said digital marketing now offers brands not only the scale and reach they need, but also providing the data they need to optimize campaigns for efficiencies. “These first-party insights allow for significant connections with consumers and long-term value for both,” said Hogan.

The IAB enlists PricewaterhouseCoopers to measure digital spending. The Q1 revenue estimates are based upon a survey of the largest companies, which are then projected to the overall market based upon recent historical revenue market share. The IAB says the results are considered a “reasonable measurement” of interactive advertising revenues because the data is compiled directly from information supplied by companies selling advertising on the internet.

“These historic Q1 figures are in keeping with digital’s ongoing rise,” said David Silverman, a partner at PwC US. “Its diverse platforms are attracting audiences to share, shop, listen, learn, and be entertained. Brand dollars are naturally following mainstream consumer consumption.”

Podcasters will get a better idea of how strong advertising growth has been for digital audio when the IAB releases its more detailed mid-year report later this year.