• by Laurie Sullivan  @lauriesullivan, August 1, 2012

It's no easy task for North America to surpass Asia-Pacific, which supports a strong telecommunications mobile infrastructure, but marketers in the U.S. will spend more on mobile advertising this year and outpace others worldwide in 2013, according to estimates released Wednesday.

The eMarketer findings forecast that mobile Internet ad spending worldwide will reach $6.4 billion in 2012, yet account for only 1% of total ad spending worldwide. The United States will grow 96.6% to contribute $2.3 billion this year, up from $1.1 billion last year.

Estimates from eMarketer combine advertising on search engines, search applications and carrier portals. Mobile display ad spending includes banners, rich media and video on WAP sites, and mobile HTML sites and embedded in-application and in-game advertising.

The uptick in smartphone use continues to propel the amount marketers spend in mobile advertising. More than 110 million people in the U.S. owned smartphones during the three months ending in June 2012 -- up 4% sequentially, per comScore. The research firm estimates browsers were used by 50%, up 0.9 percentage points.

If the U.S. keeps pace with estimates, eMarketer believes North America will surpass Asia-Pacific in 2012 as the world's largest regional market for mobile advertising.

Mobile ad spending in Asia-Pacific will reach $2.5 billion in 2012, while the amount spent in Western Europe and Eastern Europe will reach $1.3 billion and $121 million, respectively, this year.

China will become the world's second-largest advertising market in 2013, contributing $53 billion -- outpacing the amount spent in Japan for the first time. Japan will grow 27.2% to $1.74 billion in 2012, compared with 35% in 2011.

Asia-Pacific's mobile advertising market remains larger than Europe's. Although contributing only 2.3% to the total ad spend today, the U.K. market should reach 11% by 2016.

Despite economic concerns, the strength of ad spending in Asia-Pacific and support from advertising around the Olympics will help grow Europe's total ad spending to 7.4% in 2012.

Overall, global digital advertising will take a 20% share of total ad spending this year. eMarketer estimates companies will spend $107 billion for online advertising worldwide this year, up from $88 billion in 2011.