Advertisers and agencies have become increasingly concerned that they might be paying for ads that no-one sees. Equally, they want to ensure their ads are actually seen by their target audience. Viewability is a measurement that tracks impressions and counts the number of ads that are visible to a user.
The IAB* describes viewability like this: “A delivered ad view can be classified as a viewable impression if the ad is visible in the browser window, the browser tab is in focus and the minimum requirement for the number of visible ad pixels and the length of time is met. A viewable ad impression is considered an “opportunity to be seen” which is not necessarily the case when it comes to only one delivered ad display.”
*IAB, Interactive Advertising Bureau
Why aren’t all ads viewable?
The reasons ads are not always viewable can be due to several factors. The ad could be placed so far down a page that the user would have to scroll all the way down the page to see it, something they might not do. Or the ad could be placed halfway down a page and therefore only be half visible in a browser window. Or perhaps the user has already scrolled past it. It might also be that the ad is loaded in a different browser tab if the user has opened several windows at the same time, or if the user leaves the site before ads have been fully loaded.
Above / Below the fold
Simply put, there are four positions for ads on a website (top, bottom, left and right). When a page initially loads, ads and other content could be placed ‘before scroll’ ie. only visible in the top part of the page, as seen directly by the user when the page initially loads. This is commonly referred to as ‘above the fold’. The opposite is ‘below the fold’ and refers to ads and content that are placed outside that initially visible browser space, ie ‘after scroll’. This all assumes that ads are not obscured by overlays or that ‘lazy loading’ is not applied. Lazy loading means that the content of the page is continuously loaded as the user scrolls down. Because of this, the location on the page and its visibility might not correspond. All the same, above the fold, is not necessarily always the best placement to aspire for. Studies of user behaviour and eye-tracking heatmaps, often show that the eye is drawn to headlines on news pages, or the content of TV schedules, more than towards ads placed at the top or to the right of core content. Sometimes it might be preferable to have placements below the fold, closer to the page content.
Another factor to consider is immediacy. Immediacy is the time it takes for an ad to capture a user’s attention. On average, an ad is only in-screen for 8 seconds – while video ads catch a user’s attention faster than static! So think about the ad’s design, colors, pictures and CTA messages and use what’s most immediately and clearly visible to attract attention..