NEW YORK: Mobile display ads record the best results for comparatively expensive purchases like cars and electronics, according to a report.

Academics from Columbia Business School, the University of Pittsburgh and INSEAD studied data from more than 50 mobile display campaigns across a wide range of industries, and which reached about 40,000 consumers in the US between 2007 and 2010.

They found that while display ads on smartphones can only deliver a limited amount of information because of the screen size, such ads work not by providing any new intelligence, but by reminding shoppers of information they already know about a particular product.

"If you've been thinking about buying a car, you already have plenty of information in your mind about it," explained Miklos Sarvary from the Columbia Business School.

"The ad's strength is not adding new data, but reminding you of what you already know and making you think about the product again."

He argued that companies can use these findings to predict whether their products are likely to benefit from mobile display ad campaigns.

"If marketers are planning a multichannel campaign, it might help to launch the mobile display ads after the product has been advertised in other media," Sarvary suggested.

"That way, some awareness and information about the product has been generated, which can be easily triggered when cued with a mobile ad."

Noting that advertisers are shifting more of their budget into the mobile channel, Sarvary said "it is becoming even more important to have a detailed understanding of when these ads are effective."

Data sourced from Columbia Business School; additional content by Warc staff