What Is MRC Viewability? Why Should Publishers Care About It?

Brock Munro
April 2, 2024
April 3, 2024
What Is MRC Viewability? Why Should Publishers Care About It?

According to Google Ad Manager, an increase in ad viewability from 50% to 90% can result in an 80% increase in revenue uplift. 

Ad viewability is thus an important metric for gauging the success of any ad campaign. Both publishers and advertisers benefit from maximizing ad viewability.

However, how does one determine unambiguously whether an ad has been viewed or not ? 

In 2014, the Media Rating Council (MRC) in collaboration with the Interactive Advertising Bureau (IAB) introduced ad viewability standards for advertisers and publishers to help determine whether a display ad has been viewed by a user or not. These standards are known as the MRC viewability standards. While a viewable impression may not guarantee whether an ad has been viewed, it greatly increases the chance of it being viewed. This could be due to reasons such as a user not being in front of their device or they simply might be looking elsewhere. This is why some buyers are moving beyond viewability toward "attention metrics". However, attention metrics are still not as standardized which lends reason as to why it is still fully adopted in the industry. In saying that, viewability is still a crucial foundation block and still very much used amongst players in the industry.

The article explores MRC viewability standards in detail, discusses metrics used to define it and compares them with the older IAB ad impression measurement guidelines.

Table of contents:

What Is MRC Viewability?

Metrics Used in Defining MRC Ad Viewability

MRC Viewability Standards

IAB Ad Impression Measurement Guidelines

Final Thoughts

What Is MRC Viewability?

MRC Viewability is a standard that defines when a display ad impression can be counted as viewable. 

According to this standard, a display ad will be counted as viewable if at least 50% of its area is visible for a minimum of 1 second on the user’s screen. For video ads, this number is for a minimum of 2 seconds.

For larger ads (those greater than 242,000 pixels), a viewable impression is counted if 30% of the ad’s area is in view for 1 second.

Before the introduction of this standard, “non-viewable impressions” were the most commonly used metrics to determine the effectiveness of display ads. 

In 2014, Google reported that 56.1 percent of impressions served across Google’s display advertising platforms weren’t viewable. This meant marketers were wasting millions of dollars on ads that were not seen by their target audience. Google’s report also put a big question mark on the quality of publishers’ ad inventories.

Metrics Used in Defining MRC Ad Viewability

The MRC and the IAB use the following metrics when defining ad viewability: 

1. Viewable Browser Space

This is the part of the web page that a viewer can see when the page loads. It’s also known as the viewport, or what was previously called “above-the-fold”.

2.  Iframes

Iframes, short for inline frames, are fixed spaces within a webpage where third-party ads can be placed. A more advanced type of iframe is SafeFrame, which was developed by the IAB to allow better communication between the publisher page and the ad creative contained within the iframe. More information on this protocol can be had from our detailed guide on SafeFrame

3. Viewable Ad Impression

A viewable ad impression is counted when an ad is served within the viewable browser space, with a predefined number of pixels rendered within the space for a specified length of time.

4. Invalid Impressions

Impressions that do not meet the criteria defined for viewable ad impressions, as well as impressions generated by bots and other automated impressions are called invalid impressions.

5. Fraudulent Impressions

Fraudulent impressions are a subset of invalid impressions that have been deliberately generated to manipulate ad impression measurement. 

In addition to the above, the MRC also uses three key performance metrics to measure ad viewability:

1. Measured Rate

The Measured Rate is the ratio of viewable and non-viewable impressions to the total served impressions. It provides an understanding of the proportion of filled impressions that was measured for viewability. It is calculated using the following formula:

Measured Rate = (Viewable Impressions + Non-Viewable Impressions) / Total Served Impressions 

It is worth mentioning that if you are using Google Ad Manager (GAM), the platform does not have a “non-viewable impression” metric, and rather “Measurable Impressions”. In this case, the formula would be:

Measured Rate = Measurable Impressions / Total Served Impressions

2. Viewable Rate

This is also calculated as a percentage. The formula for this is:

Viewable Impressions / (Viewable Impressions + Non-Viewable Impressions)   

3. Impression Distribution

MRC recommends counting viewable ad impressions and presenting them in three distinctive categories: 

  1. Viewable Impressions
  2. Non-Viewable Served Impressions
  3. Impressions with viewable status undetermined or undetermined ad impressions

The metric “Impression Distribution” is the percentage that each category represents of total served impressions.   

For instance, if a campaign received a total of 2,000 served impressions, with 1,000 determined to be viewable, 600 determined as non-viewable, and the viewability of 400 impressions undetermined, the Measured Rate would be 80%; the Viewable Rate is 62.5%, and the Impression Distribution amounts to 50% viewable, 30% non-viewable, and 20% undetermined.

MRC Viewability Standards

MRC viewability standards define the minimum criteria for different ad types to be counted as viewable impressions. 

Here is an outline of the standard viewability thresholds set by the MRC:

1. Display Ads

MRC display ad viewability standards require at least 50% of the ad's pixels to be in view on the user's screen. Further, this visibility must be maintained for at least one second.

2. Video Ads

MRC video ad viewability standards require that at least 50% of the ad’s pixels must be in view on the user’s screen, and that the visibility must be maintained for at least two seconds.

3. Large Display Ads (Greater Than 242,500 Pixels in Size) 

For large display ads, the MRC requires that at least 30% of the ad's pixels must be in view on the user’s screen. Like regular display ads, this visibility must be maintained for at least one second once the ad appears on the viewport.

While these standards were defined primarily for desktop browsers, MRC guidelines for mobile web pages and in-app ads follow largely similar guidelines. The basic criteria for such ads too is at least 50% of the ads pixels being in view for at least one second. The complete set of MRC guidelines for mobile ads can be viewed on the MRC website here.

IAB Ad Impression Measurement Guidelines

The IAB ad impression measurement guidelines were first outlined in 2004, and were among the earliest attempts to lay down guidelines for measuring ad impressions. Most impression measurement guidelines in the digital advertising industry, including the MRC guidelines discussed above have been built on these IAB standards

The key difference between the IAB and MRC’s standards is that where the IAB standards count an impression as being viewed once an ad is loaded and displayed, the MRC stipulates that at least 50% of the ad’s pixels must be viewable for at least one second. MRC guidelines thus take things a step further.

Final Thoughts

MRC’s viewability standards have led to minimization of advertising wastage by clearly defining how advertisers and publishers should measure ad impressions.

Publishers, too, have gained from MRC viewability standards. By meeting these standards, they assure the advertisers that their ads are most likely to be seen by their target audience. This leads to publishers attracting high-quality advertisers who are willing to pay more to buy their ad inventories. Also, when publishers optimize their websites for viewable ads, they generate higher ad revenues for themselves.

Publift works with accredited MRC tech vendors as part of our initiative to ensure we are delivering value to advertiser networks which in turn improves ad revenue performance for our publishers!

Publift has been helping publishers increase their ad revenue by an average of 55% since 2015. If you are a publisher with $2,000 in ad revenue, contact us today to find how you can increase your website’s viewable impressions and level up your programmatic ad revenue.

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