NEW YORK: Google is set to remain the biggest player in the US mobile ad market, while companies like Twitter and Pandora will see faster growth than Apple, a forecast has predicted.

According to eMarketer, the insights provider, the mobile advertising sector was worth just over $1.4bn in 2011, and should yield $2.6bn in 2012, before hitting $4.4bn in 2013 and $6.6bn in 2014.

Google is in line to take $1.4bn of these revenues this year, doubling its figures from the last 12 months. This amount is projected to reach $3.6bn by 2014, equivalent to 54.1% of the market.

The firm currently has over 1m mobile advertising customers worldwide, many of them in the US. Jason Spero, its head, global mobile sales and strategy, told the Wall Street Journal the outlook was very positive.

"We're seeing mobile and tablets drive strong results for advertisers in both brand building and direct response, and this is accelerating as marketers get more sophisticated in engaging the mobile user," he said.

Pandora, the digital music service, will log $226.4m in returns from this channel in 2012, and could secure $499m by the close of the forecast period.

However, its status as the second largest operator in this category is likely to be usurped by Facebook. The social network has recently launched its first ad units for mobile, and is anticipated to accrue $72.7m this year. Totals here should reach $629m in 2014.

"The experimentation phase will come to an end, and Facebook will figure out what works in mobile, both for the advertiser and the user," Debra Aho Williamson, an analyst at eMarketer, said.

At present, Twitter is in a stronger position than its social media rival Facebook, with ad sales predicted to hit $129.7m in 2012, also from a base of zero, expanding to $444m in 2014.

Meanwhile, Apple, the electronics giant which entered the category with its iAd platform, generated $38.3m via mobile ads in 2011, and will register comparatively modest growth, to $147.4m, by 2014.

Data sourced from eMarketer/Wall Street Journal; additional content by Warc staff