Mobile ad spend to reach $18 bn in 2014: Gartner

According to the report, all regions of the world, especially North America, are expected to experience strong growth in mobile advertising spend. Looking forward, it expects the high-growth economies of China and India to contribute increasingly to mobile advertising growth as their expanding middle classes present attractive markets for global and local brands.

Gartner says since Asia-Pacific and Japan is the most mature region for mobile advertising, the growth will slow between 2012 and 2017, averaging 30 percent a year

"Over the next few years, growth in mobile advertising spending will slow due to ad space inventory supply growing faster than demand, as the number of mobile websites and applications increases faster than brands request ad space on mobile device screens," said Stephanie Baghdassarian, research director at Gartner.

"However, from 2015 to 2017, growth will be fuelled by improved market conditions, such as provider consolidation, measurement standardisation and new targeting technologies, along with a sustained interest in the mobile medium from advertisers," she added.

With regard to the different ad formats used in the mobile sector, mobile display ad formats are collectively the single-biggest category of ads, and will remain so throughout the forecast period, said the report.

However, this category will shift to mobile Web display after several years of higher growth in in-app display, the report added. It further said that the uptake of the audio/video format by the end of the forecast period is higher because the tablet form factor will drive video.