By Amanda Wilson

Imagine you’re an advertiser, and you invest all your advertising budget into a big, splashy billboard. A week later, the road beside the billboard is closed for construction, and no one can drive past your billboard for the next 3 months. You would be furious that no one would see your ad. This is essentially how an advertiser can use viewability. Measuring and optimizing toward viewable impressions helps fight against unseen digital advertising.  Viewability is a metric that tracks impressions that can be seen by users. The industry standard for this metric defines an impression as viewable when 50% or more of the pixels in the ad appear in a browser for at least one continuous second after the ad has rendered.

So, what could cause an ad to not be viewable? There are a few different scenarios. The most common reason is an ad’s position on the page. If an ad is located at the top of the page (above the fold), but the user scrolls down the page too quickly and the ad is visible for less than one second, that impression would not be deemed viewable. Similarly, if an ad is loaded at the bottom of a webpage but a user doesn’t scroll down far enough to see it, that impression would not be considered viewable either. An ad may also not be viewable if an impression is served but the ad never fully renders on the page, either from a slow load time or because a user immediately clicks off the page.

Viewability is a great approach to driving brand awareness for an advertiser who wants their message to be seen by as many people as possible. Measuring viewability, in addition to the overall impressions delivered, can help to measure the exposure achieved with a campaign. One common misconception is that higher viewability will lead to stronger campaign performance within other KPIs, but this isn’t necessarily true. Optimizing toward viewable impressions doesn’t always correlate to more site traffic or a higher number of user actions.  When we target viewable inventory we limit the inventory available. With site traffic we focus on click metrics and with user actions we look to conversions, ideally we are looking across as much inventory as possible to find sites and placements that are driving our desired result. When we limit our inventory with viewability parameters, we end up bidding more on the more limited placements that are driving results. This could lead to increased cost and less of an ability to optimize. When viewability is a campaign goal it is important to focus on both pre-bid and post-bid DSP features to help and ensure a successful campaign.


We can use both data segments (pre-bid) and reporting (post-bid) features in Basis DSP to increase the percentage of viewable impressions on campaigns. When you use a data option, the ad placement is scanned and measured before bidding takes place. If the impressions is determined to meet the criteria chosen by the user, it will bid on the placement. These viewability data segments are available through a variety of vendors in Basis DSP and can be found under the Brand Safety settings. Aside from applying data segments you can target viewable impressions by selecting specific inventory the campaign can access. Within the private marketplace (PMP) library in Basis DSP, there are a number of pre-negotiated high-viewability deals available. These can be used to control your inventory sources and bid only on viewable placements (as described by the publisher).


With reporting (post-bid) technology in Basis DSP, you can measure whether the purchased impression was viewable after the ad was served. Viewability reporting in Basis DSP is powered by Pixalate. Pixalate is a leading global intelligence platform and is a Media Rating Council-accredited vendor for display ad viewability and Sophisticated Invalid Traffic (SIVT) detection and filtration for desktop and mobile web traffic. They provide a high degree of transparency in their measurement technology, supplying us with information on viewability down to the placement level within each domain. By turning on the viewability measurement feature in your Basis DSP campaigns ($0.03 incremental CPM), you will be able to see if your ads are measurable for viewability, if they registered as viewable, and if viewability correlates with the effectiveness of the ads. The Basis DSP integration with Pixalate will allow you to execute viewability-based optimization from real-time, placement-level reporting. Over time, learning which domains, placements, and exchanges result in higher viewability rates can help inform your future media strategy for your advertisers.

When viewability is the campaign goal, advertiser should focus on both pre-bid (data or inventory control) and post-bid. Selecting certain data points and inventory is a good way to start a viewability campaign, but the post-bid or reporting piece will allow for optimizations and assurance that we are meeting our viewability goals. For a full rundown of when to pitch viewability measurement and how to include it in a media plan, you can reference our Basis Audience Extension webinar on Viewability, which will be available May 2.