Digital ad revenue in the U.S. grew by more than 20% last year to a record $72.5 billion, according to the Interactive Advertising Bureau. That's the good news.
The bad news—at least for those who dislike duopolies—is that some estimates by other industry experts show that virtually all of growth in digital ad spending went to Google and Facebook, which already account for more than three-quarters of the U.S. digital ad market.
The IAB downplayed this phenomenon in its report, saying there has been a lot of "misreporting" in the media about how the two digital giants are taking most of the revenue growth.
"Some of the outside calculations we've seen being used by the media include revenues that go beyond the U.S., for example," the IAB's David Doty told Ad Age. "Another thing they don't understand is traffic acquisition costs. And another thing they don't seem to take into account is losses from some within the industry are actually hiding gains from a broader base."
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The IAB executive said that the top 10 digital players in its report only accounted for 69% of the growth, which means that 31% of that growth came from outside the top 10.
Jason Kint of publishing-industry trade group Digital Content Next has previously written about how Google and Facebook account for virtually all of the growth in ad revenues. He said his latest estimates show the two taking 89% of the growth last year.
Pivotal Research analyst Brian Wieser, however, went even farther in a research note he sent to clients on Wednesday about the IAB numbers. Wieser said that according to his calculations, Google and Facebook accounted for almost 100% of all the growth in U.S. digital ad revenue last year.
The latest figures "highlight the degree to which Google and Facebook dominate the industry presently," Wieser wrote, "as the two rose to capture 77% of gross spending vs. 72% in the year ago period, with 99% of industry growth attributable to the two companies."
That's up significantly from the previous year, when Wieser estimated that Google and Facebook accounted for about 65% of all the growth in the U.S. digital ad market in 2015.
In an email, the Pivotal analyst said that his projections are based on Facebook's publicly released U.S. ad revenue numbers, as well as estimates of Google's U.S.-based ad revenue (which the company doesn't publicly disclose). Those figures combined with the IAB's totals show that the two have an iron grip on the ad market, he said.
While the numbers for Facebook and Google do include what are called traffic-acquisition costs or TAC—that is, money the two pay to publishing partners—Wieser says that doesn't change the fact that they still control a massive amount of the U.S. digital advertising market.
"The big point is that if Google and Facebook are the primary interfaces to buyers, over the long-run they own the relationships and the related data," Wieser said. "Every partner they work with is subservient."
In other words, their control remains intact. And it shows no signs of slowing down any time soon.