Tips to improve ad viewability

online shopping An ad impression does not tell the whole story. The traditional definition of an impression is very broad. An ad placement at the bottom of the page might still count as an impression even if the user only looked at the top of the page and did not scroll down. Therefore, impressions are further classified into different types. In this article, we will talk about ad viewability, which is measured by viewable impressions. Ad viewability only counts when the viewer actually sees the ad on their screen. Typically, a viewable impression is counted when 50% of the ad’s area is visible on the screen for at least 1 second. For example, if an ad is placed at the bottom of the page, no viewable impression is counted when the user just loads the page and only sees the above-the-fold portion of the page. When the user scrolls down far enough and the bottom ad placement becomes visible on screen for 1 second, a viewable impression will then count for that ad. This ad metric is useful to determine the actual number of views and effectiveness of your ad and its placements. Many ad servers support viewability measurement. Below are some tips to improve ad viewability:

Place premium ads above the fold

With the above description of a viewable ad impression, it makes perfect sense to have a higher viewability rate when the ad is above the fold. When the page finishes loading, an above-the-fold ad will automatically be visible and if the user stays on the page for 1 second or more, a viewable impression will be counted without the user having to scroll down. Above-the-fold ads do not have 100% viewability rate because users can very quickly click on a headline or some other links to move to another page before the viewable time threshold is reached. There is only a limited area before the fold line. Thus, top ad placements are more desirable and they demand a premium ad rate compared to lower placements.

Speed up page load

As connection speed goes up, tolerance for slow websites goes down. People are expecting websites to load instantly. If the website or any of its components, including ads, do not load quickly enough, it is very likely that users will click or switch to another page or website. When this happens, you will lose your viewable impressions and that can lead to a decline of several ad metrics like viewability ratio and click-thru ratio. It is important to optimize your website and choose a fast ad server. Website optimization includes tuning and speeding up all components, from the main page to social widgets and ads. If your ads are fast but the other widgets are slow, it can affect viewability as well.

Test and optimize ad placements

There are different ad dimensions: square, vertical rectangle and horizontal rectangle. For viewability, a vertical ad, like a sidebar ad, is more likely to stay on the screen long enough to register a viewable impression even if a viewer scrolls up or down a little bit. For the same reason, a horizontal ad just above the fold is better than a leaderboard ad at the very top of the page. If a viewer begins scrolling down right after the page finishes loading, the top placement does not have enough time to stay in the viewport while the ad that is just above the fold has more time to stay visible. It is important to experiment and measure different scenarios for ad serving to see what performs better and fits into your site or app naturally. Ultimately, we want ad placements with higher viewability rates and low page’s bounce rates.
Posted in AdServer for Publisher Selling Ads Directly by John Z August 16, 2021


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    "Ad viewability rate refers to the percentage of ad impressions that are actually seen by users. There is a difference between delivered impressions and viewable impressions. " More
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    "Ad viewability is an important ad metric when measuring the effectiveness of an ad campaign. It refers to the percentage of an ad that is actually visible to users as they scroll through their feeds or visit a website. " More
  • Finding suitable placements for ad serving
    "Determining to have ads on your site or app is just the beginning of the process, as there is a lot more work to be done before all goes live and begins generating views, clicks and sales. Also included in the process is finding suitable locations for ad serving. " More