Few people would disagree that online advertising has come a long way in recent years. And yet, even as the technology races ahead, a debate continues to swirl around two very basic questions: Can an online ad still be effective if no one clicks on it? And if so, is there a reliable way to measure the effect of such impressions?
These questions might be basic, but they're also critical. After all, the vast majority of ads are never clicked on. When a user sees an ad but only visits the site hours or days later, it's known as a view-through visit or post-impression visit. If a user then converts or spends money, it's referred to as a view-through conversion or view-through revenue. Brands can verify a view-through via a cookie that is dropped on the user's browser when the impression appears.
The source of the skepticism
The major complaint about view-throughs is obvious enough: You just never know. Sure, someone saw a Zappos impression and then visited Zappos.com the next day, but how can we really know if the impression led to the site visit? Maybe that same day the user ran into an old friend who was wearing a nice pair of shoes that she'd just bought on Zappos.
Online advertising was supposed to make this sort of uncertainty a thing of the past. By relying on clicks, marketers could know exactly what worked, making the entire industry infinitely more efficient. Skeptics maintain that tracking view-throughs takes online advertising in the wrong direction -- back to the days when all you could do was make a big spend and hope for the best.
View-through skepticism may well be attributed to a critical mistake that was made early in the history of the view-through. The time between the appearance of the ad and the visit to the site is known as the view-through window, and the length of this window is important. If you see a Zappos banner and visit Zappos.com a year later, not even the most stalwart view-through supporter would suggest attributing the visit to the ad impression.
Setting the right window can be a tricky process because the right length of time really depends on the nature of the campaign. Unfortunately, when view-throughs first came onto the scene, the windows were usually set to 30 days. This might be appropriate for campaigns that are asking users to consider major purchases, such as automobile campaigns, but for most ads, 30 days is a long time to wait between the impression and the visit. The shame is that, to this day, many marketers don't realize that view-through windows are adjustable and can be set for as short a period of time as 24 hours.
The fact that media owners have tried to game the system hasn't helped quell the skepticism. The scheme is simple: You buy up millions of super cheap impressions and spread your cookies far and wide so that you can take credit whenever a user ends up on a site that is running a display campaign. Still, if "cookie stuffing," as the practice is known, was once a legitimate issue, it's now quite rare, and thus no longer a strong argument against tracking view-throughs.
