The online advertising industry continued a six-year streak of double-digit growth, according to a new report prepared by PwC US for the Interactive Advertising Bureau.

The report found that digital ad revenue in the United States reached $59.6 billion in 2015, a 20 percent increase from the previous year and an all-time high. Sherrill Mane, the IAB’s senior vice president of research, analytics and measurement, suggested that this growth is particularly impressive considering the fact that the IAB has been releasing these reports for the past 20 years.

“For a business to be at this stage in its evolution to be growing annually in double digits … is quite remarkable,” she said.

Much of that growth is happening in newer areas like mobile, which increased 66 percent to $20.7 billion. Video ad revenue grew 30 percent to $4.2 billion, while social media ads were up 55 percent, to $10.9 billion.

So while venture capitalists and the public markets may have turned unenthusiastic towards ad-tech, advertisers are still eager to spend their money online.

There’s also been concern that the shift to mobile means a smaller pie of ad dollars for publishers, but PwC US partner David Silverman said, “I think the pie grows as you move into new channels” — particularly as advertisers become more concerned with reaching consumers on any device, so the distinction becomes “less and less relevant.”

Asked whether broader financial turmoil could threaten this growth, Mane declined to make predictions about the US economy, but she said, “The smarter brands, the ones who got through recessionary economies, typically up their advertising and promotional spend when people were tightening their belts — you needed to be there when they were going to spend money.”

Even during the last recession, ad spending dipped in 2009, but it bounced back the next year and has been growing ever since.

Mane acknowledged that there’s plenty to be uncertain about, but she said, “Let’s assume everything is reasonably known and stable, then the likelihood that this growth will continue is very high for 2016.”