The Association of Online Publishers (AOP) has released the results of a study into the effectiveness of cross-device advertising carried out by in conjunction with PHD, Manning Gottlieb OMD, Celtra and Research Now.

The study was based on two campaigns, run by car maker SEAT and department store John Lewis, which between them served over 18m impressions between mid-October and mid-December 2014. The SEAT campaign targeted ABC1 adults, while the John Lewis campaign targeted ABC1 females.

The rich media ads, built using Celtras AdCreator platform, were served across 18 sites, with the intention being to measure the uplift in the effectiveness of the campaigns among consumers who were exposed to the ads on more than one device.

Exposure to the ads was frequency capped to four impressions per consumer, using Research Now’s panel, who have meters on their PCs, tablets and smartphones which allow the company to monitor their online behaviour without the panel being aware that they are being studied ahead of the study. 2300 consumers were surveyed for the study.

The panel was split into seven cells: a control group, not exposed to the advertising on any device; one group each exposed to the ads on one of the three devices only; a group exposed to the ads on PC and tablet only; a group exposed to the ads on PC and smartphone only; and a group exposed to the ads on tablet and smartphone only. An eighth group, exposed to the ads on all three devices, was also planned, but was scrapped owing to insufficient numbers of consumers accessing the publisher sites across all three devices.

The study also included a forced exposure test to measure the impact of the ads depending on whether they were seen on premium or non-premium sites. This part of the study exposed to the ads to half of the sample on a mock-up of a premium site, and to the other half on a non-premium site.

The study found that mobile advertising cuts through the noise. The members of the panel exposed to ads on mobile only were 80 per cent more likely to recall the ads than those not directly exposed to the ads and 133 per cent more likely to recall the ads when shown an image from the ad. While this is not particularly surprising, the key point is that the recall figures for mobile-only were better than for both tablet-only (40 per cent and 33 per cent) and PC-only, where the recall figures were no different than for the control group not exposed to the ads.

Exposure to the ads on two devices as opposed to one also increased effectiveness, with awareness of the ad rising from 20 per cent to 60 per cent, and the proportion of respondents saying the ad made them think differently about the brand rising from 5 per cent to 52 per cent.

The study also revealed that each device played a different role, with the PC best for finding general information, the tablet for interaction, and the mobile for location-based activities such as finding the nearest dealer or store.

The forced exposure results revealed that consumers are 217 per cent more likely to trust the content on a premium site compared to a non-premium site, and that they are 236 per cent more likely to trust the ads on a premium site.

“These findings are really valuable as they will help to shape our 2015 plans, ensuring we are allocating our digital budgets across devices, to meet varying objectives, and carefully considering the creative and call to action for each screen,’’ said Andy McGregor, national communications and digital marketing manager at SEAT.

Lolly Mason, head of publisher development at Celtra, added: “Were big advocates of scalable cross-screen advertising so it’s really interesting to see that multiple-device exposure had such a significant impact on ad awareness. The fact that mobile showed a particular impact on brand metrics, regardless of whether or not immediate conversions took place, strengthens our position that mobile should always be included in brand campaigns where possible.”