Smartphones and tablets are playing an increasingly important role in driving mobile ad spending, with mobile searching and mapping the strongest earners.

Video and audio mobile ads, meanwhile, are the fastest-growing ad segments, with momentum seen continuing through 2015.

Given the high mobile penetration rate in Asia-Pacific, mobile advertising in the region including Japan is forecast to account for up to 49.2% of the global market worth US$3.3 billion this year, up from $1.6 billion last year.

The region is expected to continue leading with a 33.6% share of the global mobile ad market, which will be worth $20.6 billion by 2015, according to global research firm Gartner.

Andrew Frank, a research vice-president at Gartner, said that as adoption of smartphones and media tablets increases, so does the potential mobile ad audience.

"This will also drive the growth of mobile spending for advertisers," he said.

Mr Frank suggested that brand marketers wanting to cash in on the mobile ad trend should allocate spending to take advantage of mass adoption of smartphones and media tablets.

"Mobile search is expected to spearhead mobile ad spending," said Stephanie Baghdassarian, a research director at Gartner.

Mobile display - including both standard Mobile Marketing Association banner formats and non-standard rich media and interactive formats or mobile video - will continue to be closely divided between in-app and mobile web (in-browser) placement, reflecting consumer usage.

Mobile advertising is expected to pick up as more players enter the market. Ms Baghdassarian said mobile ad budgets were expected to surge globally across various categories and countries, increasing to 4% of total ad spending by 2015, up from 0.5% last year.Mobile ad spending soars in the region