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Understanding Viewability - how should you use it for your campaign?

June 04, 2014
Man looking through binoculars


How do you know if your ads are being viewed?

Many advertisers are asking themselves that very question – and, so far, the best answer has been “viewability.” Viewability is a metric with the goal of only tracking the impressions that are seen by users. So for instance, if a user goes to a page, and doesn’t scroll down, then any below-the-fold ads wouldn’t contribute to the final impressions count. As intriguing as the idea sounds, there’s still some discrepancies amongst existing technologies.

Many Ad Verification platforms claim to provide viewability measurement within their suite of tools, but reality is, few provide true or accurate offerings. Furthermore, viewability pricing models vary from flat fees to additional CPM rates and can often be absorbed by media partners on a case-by-case basis.

There are currently 2 main contenders in viewability measurement technology solutions – Page Geometry and Browser Monitoring. In addition, there are more uncommon methods such as Panel, Behavioral Proxy, Browser Exploits, and Publisher API. You can read in detail about the 6 types below.

Keeping in mind the wide variety of methods, the existing technologies, and your specific campaign, it should be clear that viewability may not be the right fit for your campaign. Due to the nature of DSP/network buys within the auction-based biddable model, the inventory purchased is extremely cost efficient. Impressions are bought ‘in bulk’ using algorithms and optimizations for direct-response campaigns that determine which user has the highest likelihood to convert. If a user shows the highest likelihood to convert, whether it is through intent/modeling/data targeting, there should be far less emphasis on if a user actually views every single ad. This is opposed to branding-oriented campaigns with goals emphasizing ‘viewable’ reach and not efficient CPA and conversion volume.

Ultimately making the decision of whether or not viewability is right for you depends on your campaigns’ goals. But, if you are interested in measuring viewability on your next MBuy campaign, we currently utilize Integral Ad Science’s Viewability Measurement solution, although we can work with your preferred vendor

Types of viewability:

Page Geometry

Page geometry is the most common technique for measuring viewability and is computed from comparing the position of ad’s four corners relative to the webpage, and then comparing the four corners of the browser’s viewport relative to the webpage. The result would say whether the comparisons are within the viewport. The limitation of this method is when ads are embedded in commonly used nested cross-domain iframes. When ads are in iframes, the viewability script will encounter difficulty or be unable to communicate with the webpage.

Browser Monitoring

Browser monitoring may be the most accurate way to measure viewability as the data is streaming from information that the browser is already collecting. In this case, recent web browsers are constantly developing new ways to do more with less processing power. By examining where the power is being allocated, we can identify how much of an ad is within view. Unfortunately, the measurement, while accurate, is limited due to browser manufacturer differences, and versions, which all have different approaches in allocated resources to the ads.

The last 4 methods, Panel, Behavioral Proxy, Browser Exploits, and Publisher API are much less common. For instance Panels rely on a small group of people with special software installed on their computers and other devices to measure.

Behavioral Proxy

Behavioral proxy is similar to Panels, but includes detecting user actions such as tracking mouse movement that may pass over an ad. The one drawback may be the positioning of the ad, as certain ad placements may generally be biased when mousing over a page.

Browser Exploits

Browser exploits are risky and unreliable as they are limited to taking advantage of a browser’s security weaknesses, but the method surpasses the limitations of any iframes.

Publisher API

Publiser API goes directly to the publisher by allowing third-parties to place a code on the publisher’s website that will execute on all page views. For instance, the IAB’s SafeFrame solution will open communication between a publisher page and iframe and provide the same security that cross-domain iframes provide publishers today. The limitation to the system is that all publishers would have to overhaul their current frameworks to accommodate the new standards.