The Media Ratings Council says it’s found the root of the viewability discrepancies that have had media buyers and publishers pulling their hair out for months. In short: measurers have been reporting on cross-platform viewability before the industry was ready for it.
Publishers have been struggling to adapt to marketers’ demands for viewability reporting across all online ad campaigns. One of the biggest — and most unexpected — hurdles has been that the dozens of measurement companies often report different levels of viewability on the same ads, due to minute differences in the way they measure.
Without consensus on how much of a campaign is actually viewable, it’s hard for advertisers to trust that publishers are succeeding in making more of their ads visible to consumers, much less accept a price guarantee based on viewability rates.
The MRC, an industry organization that audits and accredits measurement providers, has spent the last several months looking into what’s causing the discrepancies. It now says it’s found the biggest culprit: mobile. More specifically, vendors that say they can measure viewability in mobile, even though there are no accepted industry standards for how to do it.
The MRC arrived at its conclusion by reviewing data on 4 billion impressions from thousands of campaigns that ran between the end of 2014 and April of this year. Although it didn’t find the discrepancy problem to be widespread, it did find that it’s far from a myth — measurers significantly disagreed on viewability rates on more than a third (37%) of the reviewed campaigns that had more than 100,000 measured impressions.
In fact, when measurers did disagree, there were shockingly large gaps between the numbers they gave. Looking at just the campaigns where there was a significant discrepancy, the MRC found that rates measured by multiple vendors differed by 34% on average. The median difference was 23%.
But the campaigns that caused that level of disagreement had a few things in common that tripped measurers up. Those who attempted to report on cross-platform viewability (i.e. offer a combined view of how much inventory was viewable on both desktop and mobile devices) used inconsistent methodologies to determine viewability for mobile impressions. In fact, the MRC says inconsistent mobile measurement was primarily responsible for half of the discrepancies it found (54%).
“If you look at just a desktop to desktop impression comparison, vendor to vendor, that 54% basically goes away,” said MRC senior vice-president and associate director David Gunzerath. He said the problem isn’t so much that vendors aren’t measuring mobile properly, but there’s currently no accepted standard for how to measure it, so everyone is trying to do it in different ways.
“Even if everybody just adopted the desktop guidance for mobile, you’d still have issues, because some people are co-mingling the mobile impressions in a campaign, and some people aren’t,” he explained.
The MRC has not yet accredited any measurer for mobile viewability, and it only recently issued its first set of interim guidelines on how measurers should go about it. Gunzerath said there are unique challenges in mobile — like the absence of Flash — that have to be addressed before an industry standard is adopted. The report recommends that until then, measurers refrain from reporting cross-platform numbers and measure viewability in mobile and desktop separately.
“We don’t want to ignore the fact that mobile is such a big part of the landscape,” he said. “It’s just we’ve got a little more work to do before we can be comfortable that the way people are measuring mobile viewability is on par with the way those we’ve accredited are measuring desktop viewability.”
He said the MRC currently has a working group looking to address the specific challenges of mobile viewability, and it plans to issue draft standards for mobile, and begin accrediting measurers, by the end of this year.
Mobile doesn’t bear all the blame
The second biggest cause of differences between desktop viewability providers’ measurements was “multi-view ads,” which are publisher-customized ad units that combine multiple ad placements on a single web page.
For example, this incluces page takeovers with multiple matching ad placements for the same advertiser. The problem with such ads is that some measurers require all the different component ads to be viewable to consider the whole multi-view ad viewable, while others only require that 50% of the cumulative area of the various placements be on-sreen.
Gunzerath said the MRC identified this problem in a previous round of reconciliation testing, but many of the campaigns it looked at in the study ran before those guidelines came into full force. He says that today, all MRC-accredited measurers have been advised on how to deal with multi-view ads, so there should be virtually no discrepancies caused by this today.
Conflicts between measurers were another big problem, responsible for 12.5% of the discrepancies. Essentially, when some of the measurers detected a tracking pixel from a competing viewability provider, they would ignore the ad, or count it improperly. Gunzerath said that the MRC is still looking into what the technical causes of this problem are, but he expects they’ll have a way to iron it out within the next month.
With the MRC’s report on the causes of the discrepancies complete, vendors will know which changes to implement to reconcile their practices, and Gunzerath said we should see significantly fewer discrepancies significantly going forward. However he added that the technology continues to evolve, and the MRC will continue to study the way measurers track viewability through its followup audits of accredited vendors.
