Digital will capture a larger portion of global advertising spend this year than previously expected, at least according to ad conglomerate WPP’s media buying group, GroupM. The company just released a 70-country projection report that suggests digital will account for 17% of global advertising this year — one percentage point higher than the 16% the group forecasted back in December 2010.

GroupM also estimates that digital advertising is growing at a rate of 15-16% annually, looking to exceed $100 billion in spend by 2012. They predict total ad spend across all channels will hit $540 billion in 2012, up 6.8% from 2011, and thanks to the summer Olympics and US political campaigns.

“Digital advertising spending accounts for 20 percent and more of measured advertising in countries where it is most developed, but it still has real growth potential even in those nations,” said GroupM director Adam Smith. The report cites behavioral targeting and video advertising as key drivers for this digital spend.