What is Ad Viewability?
Ad viewability is the term used to describe how visible display ads or mobile ads are to users. According to the Internet Advertising Bureau (IAB), an ad is considered as a ‘Viewable Impression’ if it meets one of the following criteria:
- At least 50% of the creative is displayed on screen for more than one second.
- For larger ads greater than 242,000 pixels, at least 30% of the ad’s pixels must be visible in the browser window.
- For in-stream video ads, at least 50% of the ad’s pixels must be visible in the browser for 2 continuous seconds.
Why might an impression not be considered as viewable?
If an ad impression is served but the user does not see it, the ad may not be considered as viewable. Some reasons for this could include:
- The user has installed an ad blocker
- The user did not scroll down far enough to see the ad
- Not enough time has elapsed (i.e. less than one second)
- The page has been opened by a bot
Ad viewability can be measured using Google’s ‘Active View’ solution, which measures in real-time on an impression-by-impression basis to determine whether an ad was visible to a user. This technology is integrated as standard into Google’s advertising platforms.
Why is Ad Viewability important?
In 2014, Google reported that 56% of impressions served across the Display Network were not viewable. This figure raised the eyebrows of many advertisers who had invested so much money into digital advertising, only to find that more than half of their ads weren’t visible to users. Following the revelation, ad networks began to focus on the number of ads viewed as opposed to the number of ads served. For publishers this simply means that more viewable ads add up to more money. Low viewability hurts publishers in two ways:
Firstly a growing number of SSPs will now only pay for viewable impressions. Those that aren’t deemed viewable simply generate no revenue. Even when all impressions are paid for, placements with low viewability will suffer. Buyers understandably do not want to pay for impressions that no-one sees and will have viewability targets for their campaigns. If you inventory doesn’t meet their viewability targets then they won’t bid on it. This means lower rates and less competition, which equates to less money for poor viewability publishers.
How to improve Ad Viewability?
Ad position and type
Choose ad units that have greater visibility. Whilst below-the-fold ad units should not be ruled out completely, ads that are placed above-the-fold tend to have higher viewability. Vertical ads and ‘sticky’ ad units are a good choice as they stay on the page for longer. Also, try to implement responsive ad units that resize according to the view port, so that the ad is compatible with all device types.
Optimize for speed
In a recent study, Google found that mobile sites that loaded within 5 seconds, versus 19 seconds, were observed to have 25% higher viewability. If a web page takes a long time to load, this can drastically reduce the viewability of your ad because users are likely to leave before the ad renders. Therefore, it is crucial to optimize your site for speed.
If you haven’t already, you should also implement lazy loading so that ads only serve when necessary, which improves viewability percentage.
For more suggestions on how to reduce site latency, try Google’s PageSpeed Insights.
Good design principles
Publishers should ensure that their web page has good design principles and a clean layout. Shorter content tends to yield higher viewability, but if you must have longer form content then make sure that there is a clear visual hierarchy with adequate proportions.
Perhaps the most obvious but if your content is engaging, then the user is likely to stay on the page for longer which increases ad viewability.
For publishers, there are many factors involved in delivering and maintaining viewable ad impressions. Being transparent with advertisers about viewability helps marketers understand how effective a campaign is and allows advertising spend to be allocated to the most valuable media.