Iframing The VAST Problem Of Video Viewability

video hearabilityRemember the scene in the movie “Kill Bill, Vol. 2 where the vengeful heroine, the Bride, is buried alive in a coffin and has to pound her way out with her bare fists?

That’s your video ad.

It’s essentially trapped in a box and buried in the publisher’s web page, and whether it can get out and reveal any metrics to the advertiser depends on whether it can bash through the various impediments blocking it from the surface.

For the Bride, it was wood and dirt. For a video ad, it’s the iframe and the video player. After all, that video ad resides within a player situated in an iframe. (The iframe is a walled-in space on a web page, keeping the advertiser from manipulating the publisher’s site or accessing potentially sensitive information displayed on the page.)


Anyone familiar with the online ad industry is at this point familiar with the complications measuring the viewability of content set in iframes. They’ve plagued display ads for years and prompted the Interactive Advertising Bureau (IAB) to release the SafeFrame standard, essentially a window into the iframe’s walled garden, used by publishers like Yahoo.

Eric Lange, VP of product management for advertising products at Yahoo, also points out a methodology called inside-out measurement for JavaScript ad tags, “used fairly heavily in the display world and less heavily in the video world, at least right now.”

“There are some browser intricacies that have to be managed to make it work,” he added, “so it’s a complex technology, but it’s one that’s been developed and hardened over the last couple of years.”

Not everyone – particularly agencies and marketers – are satisfied with these workarounds.

“There are issues with iframes right now and a lot of media can’t be tracked,” said Randi Cohen, Neo@Ogilvy’s head of analytics in North America. She acknowledged the IAB’s frame guidelines but added: “They’re not as widespread as we’d like it to be. I would hope the overall tracking component would improve.”


Even if the video ad can crack through the iframe, it still needs to crack through the player, and this creates another issue. The problem, points out Pieter Mees, CEO of Zentrick, is that “most video doesn’t have the infrastructure to run code.” This makes it difficult to run interactive video  Zentrick produces a tool that enables the creation of interactive video – and analytics.

Consequently the ability to gather any salient metrics, not just those related to viewability, depends largely on the publisher’s video integration methodology. If the video was integrated using only the Video Ad-Serving Template (VAST), then marketers might as well dump their video ads into a titanium box for all the visibility they’ll get. VAST video placements, according to Kandi Onwuama, Extreme Reach’s VP of software architecture, don’t allow third-party tech vendors or advertisers to apply viewability technologies.

“There’s absolutely no way to tell whether an ad was in view with a VAST integration,” added Quinn Sanders, director of product management at Videology, one of the three vendors accredited to measure video views by the Media Ratings Council (MRC). The other two are Moat and Telemetry.

If however the publisher uses a VAST overlay called the Video Player Ad-Serving Interface Definition (VPAID), marketers have a chance.

To be clear, VAST is a delivery standard, a methodology that transmits data from the publisher to the demand-side ad server. VPAID is a creative standard, built as a VAST subset. Because it supports rich media and analytics, it also provides the ability to measure viewability.

“The type of information we can get from a publisher with a VAST integration is far less than with a VPAID integration,” Sanders said.

But how much available inventory is VPAID and how much is VAST? Estimates fluctuate, depending on whom you ask.

In the US, Sanders said, 60% to 65% of available video inventory is VPAID. Globally, VPAID inventory is 55%. A representative from video demand-side platform TubeMogul said on average 59% to 71.3% of video ads on exchanges are VPAID-compatible and measurable for viewability. Of the video ads measured by Extreme Reach, 62.1% are VAST, and therefore unmeasurable by third parties, and 37.9% are VPAID.

However one looks at it, a pretty decent chunk of inventory is measurable for viewability. But there’s also a pretty decent chunk that isn’t.

And a lot of the inventory that’s not measurable runs on premium sites.

“A lot [of premium publishers] run VAST inventory, which is inventory in high demand,” Sanders said. “So if you’re only buying viewable impressions and that means if you’re using it as a currency, you’re completely eliminating right off the bat some premium inventory. We need more publishers over to the VPAID standard.”

Viva La Resistance

One notable holdout resisting VPAID? YouTube – much to the chagrin of ad tech vendors.

“The VAST vs. VPAID discussion is more political than technical,” said Matt Augliera, SVP of media and accounts at Telemetry, adding that almost all inventory, ideally, would run on VPAID technology.

Unfortunately, we do not live in an ideal world.

“If media vendors like YouTube and Hulu don’t support VPAID,” said Extreme Reach’s Onwuama, “they need to work with measurement companies to allow for custom integrations where we can place the tech directly on the page.” [Ed: Augliera stated Telemetry has been working on a custom VPAID integration with Hulu for “quite some time now.”] Extreme Reach, along with Telemetry and Videology, are all in YouTube’s third-party ad vendor network.

Analytics provider Moat also uses the tactic described by Onwuama, tracking VAST through video player integrations – in both custom and commercial players, video ad server integrations that don’t depend on VPAID support and SDK integrations “to name a few options” – according to company CEO and co-founder Jonah Goodhart.

But Augliera also added that if a third-party vendor claims to assess viewability through VAST, it means the publisher or vendor is communicating whether or not the ad was viewable. “In essence, it’s a student marking their own homework,” Augliera said.

Some vendors claim measuring VAST inventory is feasible even without integrating ad tech directly on the publisher page.

WebSpectator CEO and founder André Parreira stated his company’s technology can measure VAST inventory because “on top of our VAST player integration, we have a unique realtime bidirectional connection that WebSpectator establishes with the user device/browser.” Essentially, it’s a direct pipe into a consumer’s device or browser that Parreira said can enable the gathering of “as many data points as we want in order to detect viewability, engagement and track time.”

While Parreira stated WebSpectator “recieved MRC accreditation for effective multimedia exposure and engagement time for any media element,” the company’s accreditation for its WebSpectator for Publishers product is accredited for viewable display impressions and, as the MRC’s SVP and associate director, David Gunzerath, told AdExchanger, “WebSpectator for Pubs was not assessed against the viewable video guidelines, and therefore they’re not accredited for viewable video impression measurement. While they did include rich media executions in their audit, these aren’t the same as in-stream video impressions.”

Whatever the efficacy of these alternate methods, they are not as easily applied or as convenient as measuring VPAID inventory. And it’s unclear why YouTube maintains the VAST standard. At the time of publication, Google had not yet responded to AdExchanger on this topic.

“It hurts the industry with YouTube not allowing proper third-party auditing to occur on their website,” Augliera said. “We don’t know why they‘re holding out, not sure whether it’s a fear in the marketplace on what will be extracted or something else.” He added that Telemetry has approached Google “several” times to create custom integrations that address its concerns, but it remains a “political holdout.”

One source who works closely with YouTube and wished to go unnamed so as not to jeopardize that relationship, speculates that Google avoids VPAID because it wants to completely control the user experience.

But Google’s holdout might soon come to an end. “I’ve seen some mentions of VPAID support in their docs recently,” the source said. “I think with enough big advertisers demanding it, they’ll have no choice but to support it soon.”

Viewability’s Validity

With all these complications, why is viewability so important? It is, as the MRC readily admits, only a baseline metric, one that determines whether the video ad had the potential to be seen, not whether the consumer actually engaged or enjoyed the content.

Adconion Direct COO Alex Loeffler described viewability, as defined by the MRC (50% in-view for two continuous seconds), as a good starting point. “But it will likely need to expand beyond this if we are to compete with TV for big budgets,” he said, “as there is more to online video than just whether it was in-view in the browser.”

Even if viewability were 100% measurable across all available inventory, most sources believe that it is in and of itself an inadequate measurement. Even vendors accredited by the MRC for video views, like Videology, dissuade advertisers from focusing on it.

“We think it’s too early to use viewability as a currency,” said Sanders. “I know the MRC lifted its advisory, so they’re okay with transacting only on viewable ads. Our positioning is we’ll optimize against it if an advertiser or agency wants to use it as a campaign level KPI. But we don’t think it’s a fully developed enough metric.”

Neo@Ogilvy’s Cohen agreed.

“In isolation, it’s not that insightful of a metric,” she said. “We have a lot of clients who are interested and asking about viewability and want some baseline reads on it. But we counsel our clients to think about the most appropriate campaigns to measure viewability.”

For example, in branding campaigns, viewability can be important in that it functions as an additional data point to measure reach. But in direct-response campaigns, Cohen prefers metrics around ROI or conversion rates.

“We might look at viewability to make sure we’re not wasting too much media, but as long as our campaign can perform efficiently, viewability is less of a concern,” she said.

Enjoying this content?

Sign up to be an AdExchanger Member today and get unlimited access to articles like this, plus proprietary data and research, conference discounts, on-demand access to event content, and more!

Join Today!


  1. I suspect that the industry may have to move to some kind of combination of an authenticated viewer model, where we are counting the number of logged-in/cookied users based on a large authentication provider (like FB, TWTR, GOOG etc) plus publisher-side standards enforced by some body that advertisers/agencies select to do so. Hard to see who this would be in the current environment, incentives are muddled, but there is a big need for video inventory and are far too many low-quality websites out there getting video impressions for this NOT to be something that the market demands sooner or later.

  2. Interesting article Ryan. I would add though that Google have pretty good support for VPAID in Flash. Any publisher can add Google’s free IMA SDK to their Flash video player and add VPAID support without even having to use Google as a demand source. The Youtube player even contains this.
    The key point is that VPAID is generally only supported across the market by Flash video players, and the Flash based Ad loaders provided by SSP’s like Liverail. Flash video players are desktop only (and an increasing smaller portion of that) hence the 55% VPAID global inventory number quoted in the article.
    Until the rise of Javascript VPAID support in HTML5 players then any viewability products requiring VPAID support will have an increasingly smaller pond to play in.