Since the first company was accredited by the MRC for the viewable impression in 2010, the industry has witnessed a tumultuous ride with twists, turns and confusing chatter.
To help readers understand the viewable impression speak better, here are a few clarifications on common statements I have heard misused or misunderstood.
“Should we be paying for 70% viewable or 100% viewable?” really means “Should we pay for Ads Served or Viewable Impressions?”
Ads served and viewable impressions are entirely different measurements that take place in a different location at a different point in time. An ad served is measured when an ad is called from a server, while a viewable impression is measured after that ad loads, renders, and a designated portion of the ad remains in view for one continuous second in the user’s device viewport.
In the real world, it is close to impossible for 100% of ad-served impressions to become viewable impressions because of the distance and time delay between the serve event and the view event. Viewer abandonment, scrolling behavior and ads served to units that are outside the user’s viewport are the main reasons for this drop off.
No one should expect all ads served to become viewable impressions. Typical ads served can achieve 20% to 60% viewability rates and if the ad unit is in view when served view rates rise to around 80%. The IAB is currently recommending view rates of 70% or more. Whether selling ads served with a viewable benchmark, or selling viewable impressions, technology to serve only to ad units that are in view is a must.
A viewable impression means the ad appeared on a user’s screen, not necessarily that the user viewed the ad.
Viewable impressions are reported every time an ad actually appears on a user’s screen, not if the ad was “viewed,” thus ensuring the ad has the opportunity to be seen. We are all familiar with the argument that TV also has impressions that are not viewed. “On TV they don’t know if the viewer went to the bathroom and didn’t see the ad.” That is true, but with TV we know with reasonable error rates that an ad actually appeared on a TV screen. A digital served impression is counted even if the ad did not appear on a screen at all.
Viewability is important because an ad served that does not appear simply does not have an opportunity to be seen. Period.
“Views not measurable,” and “Dark Viewability,” primarily mean ads served into cross-domain or blind iFrames.
The primary reason that the viewability of ads is reported as undetermined or not measurable is because they are delivered inside cross-domain or blind iFrames.
As opposed to a friendly iFrame delivery, where the buyer has access into the parent document where the ad they bought actually rendered, a blind iFrame is designed to block that access, making measuring viewability much more difficult. This forces the use of additional methods to gauge viewability, including browser hacking and browser optimization, which help increase errors and view rate discrepancies between measurement providers.
Furthermore, in most cases, blind iFrames block the ability for the advertiser to see the actual URL of the Web page the ad is rendered on, or where the ad appeared. This lack of visibility enables fraud and increases brand safety risk. So advertisers must be aware of non measurable rates and understand that, if they are high, there are risks associated with the inventory beyond that the ads may not be viewable.