• by Laurie Sullivan  @lauriesullivan, April 3, 2014

Marketers will spend an estimated $137.5 billion this year on global advertising through digital channels, such as desktop and laptop computers, tablets and mobile phones, up 14.8% from 2013, per data released from eMarketer Thursday.

Brands invested $516.2 billion on advertising in 2013, with digital representing 23.2%, per eMarketer. The data firm estimates digital advertising this year will surpass one-quarter of budgets, representing 25.3% of the worldwide ad market.

Mobile advertising hit $17.9 billion globally in 2013, or 3.5% of the amount that marketers spent worldwide. This year, marketers will spend an estimated $31.4 billion, representing 5.8% of the total global media ad market.

eMarketer projects Google will continue to dominate the global ad market share in 2014, accounting for 31.66 of net digital ad revenue share worldwide, up from 31.98% in 2013. Facebook and others will take some market share this year.

Facebook's net digital ad revenue share worldwide could reach 7.82% this year, up from 5.83% in 2013, and 4.09% in 2012. Microsoft follows with an estimated net digital ad revenue share worldwide of 2.75%, up from 2.89% in 2013, and 2.94% in 2012. Yahoo comes in at No. 4 with 2.54%, 2.87%, and 3.36%, respectively.

As for other social sites, Twitter doubled its digital advertising market share in 2013, reaching 0.5%, up from 0.26% in 2012. LinkedIn is expected to contribute 0.36%, 0.30%, and 0.24%, respectively.

Interestingly, U.S. brands remain the single biggest spender on digital ads, with North America the highest-spending region. Nearly two in five digital ad dollars this year will come from advertisers in North America, compared with 28.6% in Asia-Pacific, where share is actually dropping slightly. Western Europe accounts for nearly one-quarter of all digital spending around the world, and other regions make up just a small share.