AppNexus Continues to Improve Viewability Measurement with Desktop, Mobile, Video and Flashless Technology


With viewability becoming an increasingly important KPI for the ad marketplace, it’s imperative that advertisers continue to invest in technology that provides reliable measurement.

If a buyer only pays for viewable impressions, the measurement of those impressions must ensure that each paid impression was viewable. If an impression can’t be counted as viewable, it can’t be paid on a viewable CPM basis.

So, having the highest measurement rate for viewability is a key goal for AppNexus.

An even better global measurement rate

In a few brief months between December 2015 and August 2016, AppNexus’ global measurement rate has climbed from 82 percent to 87 percent.

At first glance, a five percent improvement rate might well seem incremental. But that’s just not the case. It’s relatively easy to measure the first 50 percent of online ads. But the going gets trickier once you find yourself edging closer to the 100-percent accuracy rate.


If only desktop is taken into account, the AppNexus platform’s viewability measurement rate is 90 percent. The remaining 10 percent consists, for the most part, of ads that get loaded onto pages that users leave within the first second. In other words, their page time is so short that the measurement script doesn’t even have time to start measuring.

That 90-percent figure is all the more impressive if you consider this:  a viewable impression, as it’s currently defined by the MRC, requires that an ad be seen for at least one second to be counted as being “in view”.  Thus, a measurement rate that’s able to reach the 90th percentile is, by definition, approaching near-perfect.

AppNexus has cracked IFrames viewability measurement for mobile 

That’s desktop for you, but what about other important delivery channels? How well, for instance, does AppNexus stack up in terms of ad viewability in the mobile space? If data is an indicator of success, the answer would seem to be: exceptionally well.

IFrames prevent viewability vendors from establishing a common “geometrical” approach when measuring ad viewability. In an IFrame, a measurement script can’t access the page that contains the IFrame, which means it can never know for certain whether or not the ad gets displayed.

Traditionally, this problem has been solved using Flash-based viewability measurement. The operating principle is that some Flash pixels are rendered differently, whether they’re viewable or not. Over the years, this feature has been used to optimize CPU usage on PCs, and is commonly known as the “optimization” method.

But here’s the problem the industry now faces: Flash doesn’t operate on mobile devices like smartphones or tablets. As a result, measuring ad viewability in IFrames for mobile devices has been an unsolvable problem for most measurement companies.

Up until recently, AppNexus was no exception to this general rule. In December 2015, our measurement rate for mobile was only 58%, which is hardly exceptional.


But in 2016, AppNexus took decisive steps to address that point by developing and releasing a Flashless measurement metric. This new technology enhancement allows measurement of IFrames for mobile.

The results of our mobile viewability initiative have been impressive. As things stand right now in November, our unique technology has improved measurement rate by 26 percent – up to 72 percent from less than a year ago!

This level of quality for mobile ad viewability now allows the market to start trading on mobile viewable impressions. Given the fact that mobile now accounts for more than half of digital ad spending, this is – no doubt about it – an incredible improvement for the overall marketplace.

Viewability for video impressions is also now well measured on AppNexus

Because of the fast-growing importance of video creatives in branding campaigns, video ad viewability has become an important KPI for buyers.

In 2016, AppNexus deployed ad-viewability measurement for VPAID video ads on desktop. With this enhancement, AppNexus can now effectively measure 80 percent of all VPAID video creatives in terms of their viewability.

But there’s no resting on our laurels here. Video viewability remains something we continue to focus and optimize upon. Our goal is to ensure that viewability metrics are as reliable and steadfast as they’ve become for other formats. In fact, prediction for video viewability will soon become a regular feature of the AppNexus programmable bidder.

With such a high measurement rate – and with our own round-the-clock efforts to increase that measurement level – we hope the market will soon be able to trade on viewable video impressions. It almost goes without saying that a viewable video marketplace would be a game changer for the industry.

Preparing for a world without Flash-based creatives

2017 will see the disappearance of Flash in most environments. Google AdX will refuse banner ads in Flash, as well as Flash pixels on its network. Flash’s longstanding ability to measure viewability will no longer be available to those who’ve relied on it throughout the years.

But this evolution need not impact our ability to measure ad viewability successfully. AppNexus is readying its platform with Flashless measurement technology that not only provides accurate viewability reporting for mobile, but also for desktop and video too.

AppNexus continues to invest to remain ahead of the market. With or without Flash, our goal is to make sure that online advertising will remain viewable – at a high rate of accuracy – for all.

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