“Viewability is important for publishers for the obvious reason that it’s important for advertisers” states Eugene Faynberg, Director of Ad Operations at Slickdeals, the largest deal sharing platform for deals and coupons. As simple as this statement might sound, the point is that advertisers are willing to pay more for a highly viewable and brand safe inventory.

With the ad tech ecosystem calling for more transparency, publishers are optimizing for viewability and helping bring better results to advertisers in order to drive more ad revenue. 

Tools such as Moat and IAS provide optimization solutions for viewability to help publishers eliminate impression waste and maximize yield, and help advertisers have their ads seen by real people, not bots. This goes a long way, considering Faynberg says that advertisers “do not want to spend money on impressions that are not seen.”

For publishers, monitoring viewability is important for a good reason: served ads that have not been seen decrease the value of their ad inventory. In addition, some advertising agencies only pay on viewable impressions as a standard policy.

According to the Media Rating Council and IAB guidelines, the definition of viewability for a display ad is when at least 50% of the ad is visible on the screen for at least 1 second. For video ads, a viewable impression refers to an ad that 50% of its pixels are visible on screen while the video is playing for a minimum of 2 seconds.

Viewabiliity according to Google

Viewable Impressions (Source: Google)

The preferred option for many premium publishers, Google Ad Server (DFP, now under Google Ad Manager and Ad Exchange umbrella), measures viewability with a technology called Active View that also accounts for another metric: measurability (see image below). 

It means that impressions that are not measurable, either for technical reasons that can be linked to a problem with an iframe or other issues, are not counted. According to Google, the average video ad viewability is 66% across websites and apps. 



Tracking Viewability & More

Viewability is a hot topic for forward-thinking publishers. Libring now gives you the ability to track it, with some new metrics that we’ve added to our solution. These metrics include:

Measurable Impressions

The number of times an ad that appeared in locations on websites or apps that could be measured.

Measurability (Measurable Rate)

The percentage of your total impressions that can be considered measured. This can be calculated by the number of measurable impressions divided by the total number of impressions. This metric helps understand how often an ad appeared in places that were able to be measured.

Unfilled Impressions

The number of impressions that haven’t been filled by the ad server. You can also look at Unfilled Impressions % if you prefer to see things that way.

Views Fill

This can be calculated by Ad Completions divided by Ad Requests. Think of it as the fill rate of video ads.

Ad Completion Rate

The percent of video ads that have been 100% completed by a viewer. Some ad networks also provide the different percentages of completion, so you may want to take a peak at what your partners provide. Try rewarded video ads if you want to give your users a little incentive to watch!

Page RPM

The revenue per thousand impressions based on a specific page.

Impressions Per Page View

Refers to the number of impressions displayed on each page of your site.


If you are investing on advertising you want to track the CPM you are paying to acquire new users. This can be calculated as Total UA Spent divided by UA Impressions.

Viewable CPM

This can be calculated as Total Revenue divided by Viewable Impressions. It is the total CPM that you are being paid for viewable ads in your ad inventory.

Digital publishing is a complex industry the way it is. Publishers that gather better data help their companies thrive and are more prepared to give their advertisers better results. That’s why is so critical to have quick access to meaningful data. Libring helps publishers quickly get a holistic view of their business and find better insights in order to optimize performance.

See your data in action by requesting a free trial today at libring.com/free-trial.