U.S. digital advertising experienced record-breaking growth in 2021, according to a new study by ad industry trade group the Interactive Advertising Bureau and PricewaterhouseCoopers LLP.

Internet advertising revenue, 2019–2021Internet advertising revenue, 2019–2021.

Overall, digital ad revenue in the U.S. climbed 35 percent year-over-year to account for more than $189 billion in 2021, according to the report. That record-setting growth is nearly three times the modest 12 percent gains the industry saw in pandemic 2020 and accounts for the largest gains in digital ad spends in the U.S. in 16 years, when digital advertising grew for $17 billion in 2006.

Ad revenues were consistently strong throughout the year, according to the report, with much of this digital media windfall driven by gains made in digital video, which was up 51 percent, accounting for total revenues of $40 billion. Other top-growing ad channels included digital audio—which includes podcasts, streamed music and radio—which grew 58 percent to $4.9 billion, as well as social media (up 39 percent to $57.7 billion), mobile (up 37 percent to $135 billion) and search (up 33 percent to $78.3 billion).

“We fully expected 2021 to be an exceptional year for digital ad growth, but even we were surprised at the degree of acceleration,” said IAB SVP and chief strategy officer Libby Morgan in a statement. “Not only was every single digital channel up, but some were up more than 50 percent year on year.”

The report also noted that 10 digital publishers and platforms accounted for more than three-quarters—78.6 percent—of total digital ad revenue last year. However, that share remains relatively flat when compared to 2020’s 78.1 percent, and the report suggests that ad spend growth among these channels has slowed in recent years, with an explosion of new online businesses in 2021 now driving an increased share of this ad growth. Supporting this theory, the report noted that another recent IAB-commissioned study conducted by Harvard Business School found the Internet economy has grown seven times faster than the U.S. economy over the past four years and now accounts for 12 percent of the U.S. GDP.

The “IAB Internet Advertising Revenue Report: Full Year 2021” was sponsored by the IAB and conducted by PricewaterhouseCoopers US, utilizing information reported directly to PwC from companies selling advertising on the Internet as well as publicly available corporate data.