The best way to accomplish high viewability is to have ad units that are in persistent view as the user scrolls. This allows the ad unit to easily achieve the threshold of being counted as a viewable impression (at least one second) even for users who are fast scrollers or just skimming the content.
Implementing sticky ads requires a developer or an ad management plugin, as the logic that controls this behavior is code-based. If you have a developer on your team, here are some great resources to get started on AMP and standard web pages.
Publishers often overfill the right rail with various widgets, sprinkling ad units in between recommended content. We recommend decreasing the amount of widgets/content in the rail, focusing on the most desired action(s) and then have an ad unit fall in the last position of the rail so that it may follow the user down the remainder of the content/page. Long Beach Post began this accelerator already having a single unit in the rail that was sticky, and viewability was averaging about 57%. Though following the implementation of lazy loading, it now averages over 70% (the IAB’s principle threshold). Because of Long Beach Post’s approach to having a single unit that remained in view for the entirety of the content, it provided the perfect use-case for a time-based active-view refresh. Read all about lazy loading and active-view refresh in our viewability study.
Oil City News added a new (sticky) unit to the last position in their right rail following the recommendation from this accelerator and they now see an average viewability percentage of 82% for this unit.
The most common sticky ad unit seen across the web is the sticky footer, and most often on mobile. This unit remains in view for the entire time the user is on a page, unless they choose to take the action of closing it. This unit typically achieves higher than the industry desired minimum of 70%, and is again, another perfect use-case for an active-view refresh. The sticky footer must not take up more than 30% of the screen, therefore we recommend creative sizes no larger than 320×100 on mobile and 728×90 on larger screens.
We added a sticky footer to both Long Beach Post and BK Reader, where this unit now averages 81% and 95% respectfully. Not only is this a highly desirable percentage for programmatic, but it should also be seen as an up-sell opportunity for direct. The ability to guarantee this high of viewability merits high-dollar return.
AdSense offers this unit as part of their “auto ads” offering, where it’s referred to as an anchor ad. If you’re an AdSense user and want to enable this unit, but not other auto ads, you can do so by editing the auto ads settings in the AdSense UI and selecting which formats you’d like to allow.
As a reminder for Ad Exchange users, you must create a publisher declaration for inventory with sticky behavior.