For advertisers, all impressions are not created equal. This is as true for TV and radio as it is for digital media. For several years, display advertisers have discussed, debated and disagreed upon the topic of viewable impressions, with new standards set to take effect next year.
While online advertisers often tout the superiority of digital over traditional media, traditional measurement techniques serve as valuable roadmaps. Like anyone who commutes regularly by car, I understand billboards and out-of-home (OOH) advertising from the consumer point-of-view. But it surprised me to learn that OOH was the first medium to tackle viewability.
Historically, OOH GRPs were calculated based on Daily Effective Circulation (DEC), a metric based on traffic data and hours of illumination. This system has obvious limitations so the Traffic Audit Bureau, an industry group, developed the concept of “Eyes-On” to more accurately value OOH impressions. DEC is still central to OOH measurement, but Eyes-On allows it to be discounted by a Visibility Adjustment Index (VAI) which takes into account factors like size, angle, and distance from road. The benefit of Eyes-On is clear:
Eyes-On represents for advertisers, agencies and media vendors a unique opportunity to understand and demonstrate the relative performance power and efficiency of OOH compared to other media.
Context matters as well: a single OOH unit can have multiple VAI for pedestrian or vehicular audiences. Based on eye tracking studies, VAI gives advertisers the ability to estimate likelihood-to-see, not just opportunity-to-see, and distinguish good inventory from bad in the process. (This presentation from GWU walks through OOH concepts like VAI in more depth.)
Best practices adopted from traditional media hold value for digital marketers. As we work to tackle attribution, single view of the customer and similar challenges, lessons learned in mediums like television can serve as valuable guidebooks.