NEW YORK—In a time when little is as it used to be, this is still quite a surprise: eMarketer now estimates that, for the first time since it began estimating ad revenues at Google, the search giant’s net U.S. digital ad revenues will decline in absolute terms this year. Facebook and Amazon will continue to grow their advertising revenues, but at “severely depressed rates compared with earlier expectations,” eMarketer added in its recent updated advertising forecast.

Still, the three companies’ size in the advertising market this year will be similar to what it was in 2019 — increasing by $1.69 billion — but with a somewhat different internal breakdown. (Google’s advertising decline is due to “a sharp pullback in travel advertiser spending,” according to eMarketer’s forecast.)

“By the end of 2020, Google’s net U.S. digital ad revenues will drop 5.3 percent to $39.58 billion,” eMarketer noted in a recent analysis.  “That brings Google’s share of the U.S. digital ad market to 29.4 percent, down from 31.6 percent last year. Our Q1 2020 forecast (which did not account for a global pandemic) predicted Google’s U.S. ad revenues would grow 12.9 percent, but its market share would still shrink slightly.”

Nicole Perrin, eMarketer’s principal analyst at Insider Intelligence, noted that Google has been growing its net U.S. ad revenues at a slower rate than the overall digital ad market since 2016. “So, this year will continue a trend of Google losing digital ad market share in the U.S.,” she added.

According to eMarketer, despite downward revisions to forecasted growth, Facebook and Amazon will increase their net U.S. ad revenues this year, while the total digital ad market grows slightly by 1.7 percent. Among other eMarketer expectations for the digital ad market this year:

• Facebook’s net U.S. digital ad revenues will increase 4.9 percent to $31.4 billion, driven by Instagram’s growth. Facebook’s share of the digital ad market will grow from 22.7 percent to 23.4 percent year over year.

• Amazon’s net U.S. digital ad revenues will jump 23.5 percent in 2020 to $12.75 billion. Its market share will increase from 7.8 percent to 9.5 percent.

• The overall U.S. digital advertising market will increase just 1.7 percent, to $134.7 billion, as “the triopoly’s share as a whole will gain just 0.2 percentage points from the long tail of the market, the smallest gain in a decade,” according to eMarketer.