NEW YORK: Digital adspend in the US is expected to grow 15.9% this year to reach $83bn, with Google and Facebook continuing to dominate the market, according to the latest forecast from eMarketer.

The New York research firm reported that Google and Facebook will see their US revenues grow 14.8% and 32.1% respectively, as Google dominates search advertising and Facebook rules display.

Google's share of the search market is forecast to grow 16.1% to $28.55bn, giving it 77.8% of the total, while its share of the total digital ad market is expected to fall slightly to 40.7%, as Facebook pulls ad revenue away from competitors.

"Google's dominance in search, especially mobile search, is largely coming from the growing tendency of consumers to turn to their smartphones to look up everything from the details of a product to directions," said eMarketer analyst Monica Peart. "Google and mobile search as a whole will continue to benefit from this behavioural shift," she added.

Turning to the digital display market, eMarketer predicted that Facebook will take US ad share from Google, Twitter and Yahoo in 2017, with Facebook's US display business jumping 32.1% to $16.33bn, or 39.1% of the total display market.

"Facebook's revenue growth can be attributed to growth in both time usage and time spent, which continues to draw advertisers in greater numbers," the report said.

What's more, Instagram is also helping to drive Facebook's revenue growth and the image-sharing app is expected to account for 20% of Facebook's mobile revenues this year, up from 15% in 2016.

"Facebook's users are increasingly captivated by videos on the platform – not just on Facebook but on Instagram as well," Peart said. "Video, both live and recorded, is a key driver of growing user engagement and advertiser enthusiasm."

Snapchat, the image-messaging service that recently listed on the New York Stock Exchange, is also poised for "explosive growth" this year.

Snapchat's US ad revenue is forecast to grow 157.8% to $770m, although that is slightly lower than the $800m that eMarketer projected in a previous report.

Meanwhile, 2017 looks like it will be a tougher year for Twitter, which is expected to see its US ad revenue decline by 4.7% to $1.3bn.

Twitter's share of the US digital ad market is also expected to fall to 1.6% from 1.9% last year, while its share of the display market will also drop to 3.1% from 3.9% in 2016.

Warc's latest US Ad Forecast, which draws from IAB data collected directly from media owners, expects digital adspend to reach $76.2bn this year, a 12.5% rise from 2016.

Data sourced from eMarketer; additional content by Warc staff