Digital ad spend is still growing in the US, up 17% year-on-year, to reach just under $58 billion; but this growth is far lower than the same time last year, according to the IAB.

The IAB’s latest report, compiled by PwC, finds that 2019’s H1 growth is lower than the 23.1% growth reported a year ago, and is slightly lower than the preceding half year, according to PwC Partner, Assurance Services, David Silverman.

Internet advertising revenues in the United States totalled $29.9 billion in the second quarter of 2019, an increase of 6.7% from the 2019 first quarter total of $28.0 billion, the report states.

There is good news on the mobile front, with ad revenues growing 29.1% to a total of $39.9 billion. As a result, mobile’s share of total US internet ad revenue now totals 69%. By contrast, desktop revenues have declined again to just 31% of the total, equal to $18 billion.

“The rapid growth of the mobile advertising platform has resulted in mobile specific CAGR of 47.2% since 2015. The saturation of mobile smartphone devices was a major factor in this historical growth. Continuing to fuel future mobile growth will be the rollout of 5G and the increased speed at which consumers can watch video on their personal devices.”

Digital video continues to grow its share of both mobile and desktop ad spend. In total, video grew to $9.5 billion in H1 2019, a 35.7% increase on the H1 2018 figures. What this report demonstrates is the acceleration of mobile in the video space: mobile now takes $6.4 billion of the total video spend compared to desktop’s $3.1 billion.

Meanwhile, social media’s growth in the US market continues, with a growth of 25.7% year-on-year. From 2012 to 2019, social has shown a 44.7% CAGR.

Elsewhere, the good news is for digital audio revenues, which despite a low base has grown 30.1% since the same time last year, with the bulk of this growth through mobile, which has seen a 40.9% YOY increase.

Looking broadly at the figures, GroupM’s President of Business Intelligence, Brian Wieser, speaking at a media briefing on the figures, noted that the fundamental message is unclear. Most probably, high growth elements of the internet economy are maturing; concurrently, “it does feel like we are long in the tooth on economic expansion.

In comments reported by MediaPost, Wieser went on to to observe that digital ad growth is not necessarily endemic, with the largest catalysts – fully digital marketers and small businesses – probably having reached the ceiling of their impact on the online economy. At the same time, many large firms’ digital transformations are either well underway, or already spending all they can do on digital channels while maintaining broad-reach brand spend.

Sourced from the IAB, MediaPost