NEW YORK: Google, the internet services giant, accounted for more than half of the $8.8bn spent globally on mobile internet advertising last year, and its share is expected to rise as the world market almost doubles in 2013.

Insights provider eMarketer estimated that Google took a 52% share of net mobile internet ad revenues in 2012, and that this would rise to 56% in 2013.

Total mobile internet advertising spending has increased dramatically, from just $1.53bn in 2011, to $4.61bn last year and a forecast $8.85bn next year.

Other companies are also growing fast, albeit from a far smaller base. Facebook, the social media site, had no mobile ad revenues in 2011, but recorded $470m in 2012, a figure which is predicted to increase 334% to $2.04bn in 2013.

In 2013 Facebook is predicted to earn more in mobile ad revenues than Google did just two years ago, but will account for only 13% of the total market.

Just as Facebook is a long way behind Google, so Twitter is a long way behind Facebook. eMarketer suggested that growth for the micro blogging site would be much slower than its competitors.

Twitter's net mobile internet ad revenues have grown from zero in 2011 to $140m in 2012 and are forecast to reach $380m in 2013, by which time it will take a 2% share of the market.

Combined, these three companies account for "a consolidating share" of mobile advertising revenues worldwide, said eMarketer. It predicted that the share of other players, including YP, Pandora, Apple and Millennial Media, would decrease.

However, eMarketer added that these firms would still see their mobile advertising revenues growing rapidly.

In particular, it said that YP, the online directories service, which accounted for 2.9% of mobile internet ad revenues last year, was well positioned in the mobile search market.

Google and Facebook are also the leading two companies in terms of ad revenues across all digital platforms, taking shares of 31.5% and 4.1% respectively in 2012. And eMarketer expected that Google's share would increase further, partly due to its continued monetization of YouTube.

Despite the dominance of Google and, to a lesser extent, Facebook, eMarketer observed that over half of all digital ad revenues worldwide went to companies in the "other" category.

"There is space for other players to emerge and potentially gain significant share," it said.

Data sourced from eMarketer; additional content by Warc staff