NEW YORK: As consumers spend more time on their mobile devices, the level of online conversions taking place via this channel has increased significantly in the past year, a new study has found.

For the report, AOL and the University of Virginia School of Engineering and Applied Sciences analysed more than 500bn online ad impressions served by AOL Networks between 2012 and 2013, and 100m 'conversion events' across mobile phones, PCs and tablets.

The results indicated that mobile's share of conversions had risen by 28% and now stood at an average of 31% across the telecom, retail, auto, and travel sectors. Categories such as consumer packaged goods were not considered for the study.

Chad Gallagher, director of mobile at AOL Networks, said this figure was "much higher than what I thought it was going to be, and much higher than what marketers think it's going to be."

He suggested to MediaPost that it was around twice what might have been expected.

For the sectors reviewed, telecom, at 37%, had the highest rate of mobile conversions, closely followed by retail on 35%.

Auto registered 22%, with conversion here being defined as finding a local dealer, requesting more information or configuring a car, while travel scored 20%.

Tablets, and especially iPads, were found to be especially effective for ads. Some 65% of conversions took place on these devices, with the Apple product taking the lion's share on 85%.

Smartphone conversions, however, were evenly split between the iPhone and Android-powered devices.

The study also found that, despite the appellation of mobile, 75% of all mobile ad impressions were viewed at home.

"The reality is, it's mom, at night, with the TV on," said Gallagher, adding: "When you change that image, it changes everything about how you think about mobile."

Gallagher added that many marketers were still running campaigns aimed at desktop users and suggested they needed to refocus on mobile and ensure they could track conversions across all platforms.

"You need to ensure that every single technology can run across all platforms or you're missing out on a third of your potential business," said Gallagher.

Data sourced from MediaPost; additional content by Warc staff