A new report from ZenithOptimedia has revealed that advertising on mobile platforms is helping to fuel growth in digital marketing, with spending growing six times faster than traditional desktop PPC campaigns and site ads.

Mobile ad expenditure is anticipated to grow 50 per cent, year on year, until at least 2016, with the global uptake of smartphones and tablets helping to justify significant investment in this area.

The wider ad market will be expanding at the comparatively modest rate of 5.5 per cent this year, with 2016 expected to see a 6.1 per cent overall increase, according to the report.

Analysts believe that this is strong evidence showing that the recovery from the recent recession has really begun to take hold, as advertisers are now keener to spend more cash on campaigns, in the hope of seeing a tangible ROI from digital avenues, especially mobile.

Within two years, paid search ads will still account for the biggest proportion of internet adspend, although the adoption display ads will be growing at a quicker pace, making up the lost ground.

Meanwhile, social media services are also being harnessed by a growing number of businesses hoping to drive traffic to e-commerce sites, with adspend in this area expected to grow by almost a third each year.

Last year, about $13.4 billion (?8 billion) was spent globally on mobile ads, covering promotional search listings tailored to mobile users as well as in-app advertising. This represents over a tenth of the total online adspend, or almost three per cent of the global marketing sector?s output as a whole.

However, with the significant annual growth predicted, analysts currently believe that by 2016, around 28 per cent of internet adspend will be accounted for by mobile. This will make it the world?s fourth most prominent platform for marketing, ahead of radio, print magazines and outdoor ads.

When looking at things on a country-by-country basis, it is clear that mobile ads are more prominent in some nations than others. The UK, for example, saw spending on mobile ads more than double last year.

So while paid search ads may still be leading the way in terms of sheer expenditure, it seems that mobile might eventually grow to the point that it eclipses desktop investment, which will mark a real turning point for the market.

What remains to be seen is which form of mobile advertising becomes the most widely used going forward. And of course, this will largely depend on how successfully it can be deployed to boost sales online.

Paid mobile search is dominant at the moment, but display ads and in-app ads are building momentum in certain areas, which means that even more upheavals are on the way.

Businesses will need to keep an ear to the ground to help determine which advertising platform is right for them, especially in an age when internet users are increasingly flocking to portable platforms, rather than relying on traditional desktop PCs to make e-commerce purchases.