NEW YORK: Rapid digital growth will lead to a 4.9% rise in US adspend for 2012, new forecasts from research firm eMarketer have indicated.

The report also suggested that adspend in the world's largest economy would maintain steady annual growth of at least 2.7% in the years to 2016, by which time expenditures were forecast to reach $189bn. This year, spend is predicted to hit $166bn.

Figures from eMarketer released earlier this month indicated that digital ad spending would rise at a slower rate than previously anticipated in 2012, at 16.6% rather than 17.7%.

But the channel remains the main driver of growth in the all-media total, with online and mobile ad revenues expected to account for 22.5% of overall media ad spending this year, or $37.3bn.

These figures broadly echo Warc's projections for the same period which forecast that total US media spend will rise by 4.1% in 2012, with online taking a 23.1% share.

Growth in subsequent years is expected to be slower as US media spending has been boosted in 2012 by the Olympic Games and the presidential election campaign.

From 2012 to 2016, digital ad spending's share of US media spend is predicted to increase from 22.5% to 29.2%, largely at the expense of print, eMarketer said.

But TV remains the top ad medium, accounting for 38.9% of the total, and is expected to continue to maintain this share out to 2016.

Data from eMarketer; additional content by Warc staff