A new study from Think with Google looked at display advertising platforms, including Google and DoubleClick, to determine what affects an ad’s viewability and found five factors that impact the extent to which ads are seen.

Specifically, the study found:

1. A small number of publishers are serving most of the non-viewable impressions. In fact, Google says, 56.1 percent of all impressions it measured are not seen, but the average publisher viewability is 50.2 percent.
2. In addition, Google says, page position matters. In other words, the most viewable position is right above the fold, not at the top of the page.
3. Ad size matters, too. Google says the most viewable ad sizes are vertical units and that means publishers should consider which ad sizes are most effective at different page positions when making ad placement and layout decisions.
4. Further, page position isn’t always the best indicator of viewability. Not all above-the-fold impressions are viewable, while many below-the-fold impressions are, Google says. In fact, Google found median viewability for above-the-fold ad units is 68 percent while median viewability for below-the-fold ad units is 40 percent.

Because viewability varies significantly by page position and ad size, Google says advertisers should consider the relationship between the two while planning creative and targeting. And because page position “doesn’t tell the whole story,” Google says advertisers should ultimately target based on viewability measurements to achieve the best results. Viewability can also help publishers better identify and monetize valuable below-the-fold inventory, Google adds.

5. In addition, Google says viewability varies significantly across content verticals, with the highest viewability belonging to sites associated with “more captive engagement,” like reference, online communities, and games.

Advertisers seeking viewable impressions should therefore steer towards high viewability sites and consider targeting sites with more engaging content to achieve higher viewability rates, Google recommends. Viewability data can also help publishers increase the long-term value of their display inventory, Google adds.

Google says it conducted research using its Active View technology because there is increased interest in viewability among advertisers and publishers after the Media Rating Council lifted the viewable transaction advisory earlier this year, which recommended the marketplace refrain from transacting on viewable impressions as a digital advertising currency metric until issues related to the measurement of viewable impressions could be resolved.

Since its implementation, the MRC says measurement techniques have evolved and “innovative ways have emerged that have enhanced the ability of measurers to determine an ad’s viewability in numerous challenging environments” and the limitations on viewability measurement had largely improved.

According to the MRC, a viewable impression occurs when 50 percent of an ad’s pixels are on screen for one second.

The data used in Google’s study was based on display ads in browsers and didn’t include mobile in-app and video ads, Google adds.

The IAB, which is part of Making Measurement Make Sense, or 3MS, a cross-industry initiative that says it seeks to revolutionize the way digital media is measured, planned and transacted across the advertising industry in order to make it a more valuable medium for everyone involved in brand advertising, says it is important for publishers to transition to viewable impressions because viewable impressions mean marketers will have more assurance that their ads have had the opportunity to be seen and they will be encouraged to purchase digital media because of its comparability to legacy media.

Not only will this allow marketers to invest more confidently in digital media and more intelligently allocate their budgets between digital and other media,

“It will likely drive a stronger and more prosperous digital advertising industry overall,” according to the IAB. “Transitioning from a served impression standard to a viewable impression standard is the number one guiding principle in the Five Guiding Principles of Digital Measurement as defined by the 3MS initiative. It will allow for, among other advances, the formation of a digital gross rating point that provides reach and frequency reporting of viewable impressions and cross-platform comparisons.”

And, per comScore, both media buyers and sellers can benefit from leveraging measurement to improve campaign and inventory performance.

That’s because optimizing for viewability improves branding impact for advertisers, comScore says. With its partner ConAgra Foods, for example, using viewability and audience guarantees achieved increases in attribute awareness lift of up to 70 percent and increases in purchase intent lift of up to 30 percent.

Per comScore, advertisers and agencies must also communicate their audience and viewability goals and establish a process for evaluating performance.

What’s more, integrated viewability and in-target reporting improves the accuracy of performance data. ComScore says analysis of campaign data showed that viewability and validation rates varied across demographic breaks, meaning that the common practice of applying a flat viewability rate from one measurement vendor across the audience data from another measurement vendor will often lead to under- or over-valuing ad delivery across audience segments. To understand the true performance of the ad campaign, advertisers and agencies should use an unduplicated validated in-target metric, comScore says.

Publishers should use tools to enhance their viewability and audience delivery. Another comScore partner, CafeMom, used comScore’s vME measurement platform to identify key advertising inventory on its sites that had room for improvement and then tested new design strategies to bring up their viewability rates. Ultimately, CafeMom more than doubled the viewability of this inventory, greatly improving the value of one of its most common ad slots, comScore says.

Publishers should also set expectations for campaign delivery. That means knowing the quality of their inventory and, once goals are set, they should make sure they have access to the same campaign data the advertiser is using to track delivery, comScore says. This empowers publishers to make changes to ensure the quality of their delivery and to meet the audience and viewability guarantees throughout the campaign.

Publishers should also continuously monitor and optimize their inventory, comScore says, to ensure advertisers are satisfied that their ads are running on high-quality inventory that will give their campaigns the opportunity to make an impact on their audience.