Ad viewability reminds me of the old question about a tree falling in the forest. If no-one sees the ad, it cannot make an impression.

Viewability is defined by the Media Ratings Council (MRC) as “the opportunity to see.” It has emerged as a key concern for advertisers over the past few years as they have realized that a majority of their ads remain unseen. A study from Google in December 2014 found that 56% of ads are not viewed, making it clear that “an ad served doesn’t necessarily equal an ad viewed.” A similar study by comScore yielded same results. Viewability, or rather lack thereof, meant that millions of dollars in ad spend were essentially going down the drain.

In response to these concerns, the industry swung into action. The MRC published “Viewable Ad Impression Measurement Guidelines” for desktop browser‐based advertising. These guidelines stated that for viewable ad impressions to be counted, 50% of ad pixels must be in view for at least one continuous second for display formats and at least two continuous seconds for video formats. In 2015, the International Advertising Bureau (IAB) released its Viewable Transition Plan, meant to serve as a road to make “100% viewable impressions” the norm based on two categories: measured and non-measured.

While a step in the right direction, these guidelines did not fulfill the glaring need for definition and standardization on mobile. Mobile advertising was exploding, but the mobile feed environment – and the way consumers interact with it – is very different from desktop‐based content consumption. The same standards could not apply, and it was unclear how much of a mobile ad should be in view for it to be considered viewable.

In June 2016,  the MRC finally published its “Mobile Viewable Ad Impression Measurement Guidelines,”designed for mobile web and in-app advertising:

• Pixel Requirement: Greater than or equal to 50% of the pixels in the ad were on an in-focus browser or fully downloaded, opened, initialized application, on the viewable space of the device
• Time Requirement: The time the pixel requirement is met was greater than or equal to one continuous second, post ad render. On video, the pixel requirement is the same, but 2 continuous seconds of the ad is required.

There are several in-app measurement vendors accredited by the MRC, or are in the process of accreditation. As viewability expands, its likely that many more companies will become accredited in the future. It can often take longer to render ads on mobile devices than on desktop, which ties directly into the consumer experience problem. Vendors have to be in constant communication with their tags in order to determine whether an ad was in view or not, and that chews up data and power.

These circumstances have led to a rise in viewability companies for mobile. The good news is that they rely on existing and accessible inventories. However, their methodologies were developed before standardization and full guidance were issued, and so they rely on industry standards, which is now outdated because it focuses not on “100% viewable ads,” but on 100% measured ads for billing.

This disconnect is a problem. Advertisers can navigate around this issue by accessing “viewable” inventory and working with leading mobile viewability companies that offer measured tracking. In addition, they can consider billing on only “100% measured viewable impressions” and consider implementing their own ability to measure viewable ads.

Many vendors are working towards achieving 100% viewability, and when this shift occurs in a meaningful way, it should have a significant impact on the market by driving up the performance of display ad campaigns.