Why Viewability Is An Important Metric For Media Buyers

Originally published in 2023. Updated in 2026 to reflect the latest industry standards, research, and best practices.

Despite various analytics metrics and key performance indicators, viewability still stands as a crucial metric in the digital advertising landscape. With consumers encountering ads across countless channels and devices daily, ensuring your ad has the opportunity to be seen by a human user becomes paramount.

Viewability is defined by industry standards that specify how much of an ad must be visible and for how long. This standard varies for different types of ads, such as display and video, across desktop, mobile, TV, and other platforms. Understanding and optimizing viewability can significantly impact the success of your ad campaigns, validating impressions and enhancing the quality of your advertising efforts.

What does it take to consider an ad viewable?

Impressions are considered viewable for both desktop and mobile when they appear within a user’s screen and have had the opportunity to be seen. Industry standards for display ads are as follows: 50% of the ad has to be visible on the screen for at least 1 continuous second. For larger display ads measuring 242,500 pixels or more, only 30% of the ad pixels need to be on screen for one continuous second for the ad to be counted as viewable. For video ads, the viewability standard is different: the ad must have at least 50% visibility on screen and must have been viewable for at least 2 continuous seconds.

Viewability as a key performance indicator

Viewability has become an important metric. Digital marketers want to confirm that ads have the opportunity to be seen and their campaigns perform as expected. Beyond validating that advertisers get what they paid for, using viewability as a metric also provides insight into the quality of impressions and evaluates the quality of a publisher’s inventory.

According to Integral Ad Science, global video viewability reached 79.7%, outperforming display viewability at 67.9%, a difference of 11.8 percentage points. This highlights how visibility can vary across ad formats. 

The Need to be Seen

The demand for higher viewability may mean that some of publishers’ inventory is no longer sellable. With a drop in the amount of inventory that advertisers are willing to buy, publishers may have to increase CPMs to make up for the gap in revenue. Delivering 100% viewability isn’t necessarily impossible for publishers, but achieving it consistently across every placement and impression remains a challenge.

However, not all advertisers are demanding 100% viewability; some advertisers may find desirable performance results, such as click-through rates (CTR), from inventory with lower viewability. In direct response (DR) campaigns, performance is often measured through conversions and metrics like Cost Per Click (CPC) or Cost Per Acquisition (CPA), rather than viewability alone. But CTR kor conversions aren’t as useful of metrics when the campaign goal is to drive awareness.

How to measure viewability

For both mobile and desktop, banners and videos, viewability is measured through various ad verification strategies by different platforms. Verification strategies are based on industry standards and provided by companies that enable third-party measurement and ad verification.

Third-party measurement and ad verification vendors, including DoubleVerify, Peer39, and Integral Ad Science, offer tools to help advertisers improve media quality, evaluate viewability, and identify suspicious or fraudulent traffic. Pre-bid controls can also help advertisers avoid unsuitable inventory, including sites with content promoting hate speech or illegal activity.

Verification helps to measure viewability and identify ad fraud, such as nonhuman traffic from bots registering clicks. Invalid traffic should be filtered from valid viewability reporting. But viewability alone doesn’t guarantee better performance.

What does viewability do for your campaign?

Viewability doesn’t guarantee increased ad performance, but viewability and performance are linked.

For example, studies have shown that how long an ad is continuously visible can have a higher impact on performance than the percentage of the ad viewed.

As advertisers increasingly look beyond impressions to measure attention and engagement, viewability remains an important starting point. After all, an ad can’t capture someone’s attention if it never has the opportunity to be seen. 

Players in the ad tech industry such as Integral Ad Science, Comscore, and the Interactive Advertising Bureau continue working toward understanding viewability, setting standards and guidelines. However, discrepancies in counting methodologies still exist, both in the final numbers and in the methods themselves.

Key Takeaways for Optimizing Ad Viewability

It’s helpful to keep some more qualitative factors that improve viewability, and improve performance, in mind. While it’s trickier to define metrics for all aspects of viewability, advertisers should keep certain aspects in mind that might impact their viewability, such as:

• Viewability is defined as a display ad that is at least 50% visible on screen for 1 continuous second, or 2 continuous seconds for video.
• Viewability as a KPI helps advertisers gauge the value of inventory.
• The demand for higher viewability could impact pricing from publishers.
• Both measurable and qualitative factors impact viewability, which can influence ad performance.
• Buyers need to keep best practices in mind when buying inventory, like keeping key branding elements prominent in ad creative and avoiding ad clutter.

Ready to optimize your ad performance? Start leveraging viewability metrics to enhance your campaigns and drive better results. Contact us today to get started.