Ad fill rate – what does it mean for publishers?

  • 27 / 09 / 2022
  • Agata Cnatalska
Ad fill rate – what does it mean for publishers?

Publishers come across many concepts and metrics when monetizing digital content with ads. Especially when using programmatic solutions! You have to understand them profoundly to squeeze as much as possible from their potential. One frequently appearing factor that content creators deal with is ad fill rate. Despite its high prevalence, it’s often misunderstood and further misused. However, when applied wisely, it can give an exceptional insight into performed ad operations and lead to generating outstanding monetization results! Keep on reading to learn more about that tricky little rate!

What is fill rate in advertising

Fill rate determines broadly understood filling, which is the amount of a given entity within what it’s in. The definition will vary depending on the industry: it’ll have a different meaning in business, retail, and graphics. But let’s focus on what is ad fill rate.

Ad fill rate is a factor indicating the percentage of ad requests that ended up with ads being displayed. Now, it can refer to various things: one particular ad placement or all ad placements supported by the same advertising system (for example, an ad fill rate of the units powered by programmatic). It can also determine the rate for all ad units of a given page, or – in the broadest sense – ad fill rate can indicate the ad fill percent of all the ad units present on the entire website.

Fill rate formula – advertising:

Total number of ad impressions / total number of ad requests * 100%


Can anyone get a 100% fill rate?

It’s definitely not an easy task, as there are many factors reducing the rate’s value. That’s the reason why an average ad network fill rate doesn’t always reach 100%. Each publisher’s task is to try to attain as high as possible ad fill rate from the entire monetized website. It can be achieved only with skillful use of its potential and the appliance of diversified monetization methods. However, improper and chaotic attempts to reach such a result may end up in displaying poor-quality ads, which might even lead to harming the publisher’s reputation. Besides, it’s not a guarantee of satisfactory financial results!

Main reasons for low ad fill rate

  • Technical issues
    These factors are mostly external and often independent of the publisher’s will. Some of the reasons for blank ads are bad calls for ad creatives, lost internet connection on the user’s side, or use of ad blockers. But it can also involve the website owner’s fault, as it may result from an unoptimized page that takes too long to load (making users leave it before the ads are displayed);
  • Small demand
    Some world regions and content topics are more attractive among advertisers, making them a common target for marketing operations of many brands. But there are also less popular ones that might struggle to get advertisers willing to pay for displaying ads to them. In the second case, the publisher has to put a lot more work into finding appropriate solutions to generate earnings from monetized content;
  • Exaggerated prices
    Setting floor prices (minimum prices required for displaying ad creations within your ad inventory) helps ensure the quality of ads shown to your audience and that separate ad units will get higher bids. However, if you set floor prices that are simply too high, you can significantly reduce the number of advertisers buying your ad impressions. In turn, this will lead to a considerable drop in your ad fill rate and, consequently, in your ad revenue. Mark my words, monetization is a complicated sandbox, and you just have to know which tools to go for and how to use them. With operations like setting auction prices comes great responsibility, so it’s just safer to leave this one to the experts;
  • Non-adapted ad units
    Some ad units do really well on a given type of device (for example, on desktop) but fail completely on others (like mobile). Suppose a considerable part of your audience receives content using devices that your ad layout is not designed (or optimized) for. In that case, it will lead to low coverage of your ad inventory, leaving many of the ad placements empty.

What to do to increase your ad fill rate

  1. Optimize your ad layout
    Make sure your ad layout is well constructed and all the ad units within it are properly implemented. It also has to be responsive and adaptable when displayed on different types of devices. It’s a good practice to focus especially on the devices predominantly used by your audience. There are many analytical tools that could help you find out which device it is. But you can also deduce this using the infallible tool of logical thinking – if you reach your target audience mostly on social media (for example, through Instagram), they will likely visit your website using mobile devices (especially their phones);
  2. Boost the ad demand
    When applying solutions like programmatic, you have to ensure that there will be advertisers willing to bid on your ad inventory. Otherwise, it doesn’t really make sense! Having access to multiple ad providers greatly increases the chances of having your ad space filled to a large extent. It’s obviously much easier to achieve when collaborating with a monetization partner, therefore make sure that the one you choose will provide you with access to many SSPs;
  3. Apply yield management
    Your ad inventory has to be well-managed to bring the best results. And the key to it lies not only in the construction of your ad layout, but also in things like a well-thought-out pricing strategy. The task is not easy, though, so for the sake of your revenue, it’s better to entrust the processes of yield optimization and yield management in the hands of experienced specialists;
  4. Choose the right solutions
    There are available options like header bidding or Open Bidding that can help you achieve better ad space coverage, as these types of auctions consist in questioning multiple advertisers simultaneously. However, all that glitters is not gold, and there’s no solution that would do wonders for just everybody. Each content and its recipients is a separate story, ruled by its own rules. So the best thing to do here is to choose solutions that will work well in your specific case.

So what does ad fill rate mean for publishers?

First of all, you have to remember that a high fill rate is not a goal itself – it’s just an indicator intended to reveal the performance of your monetization operations. This metric can help you understand if the applied solutions are doing just fine or if there’s something that should be improved.

Here’s an example of how you could utilize the knowledge of what your ad fill rate is: let’s imagine you only use a programmatic system and (assuming everything is done correctly) the ad fill rate of your website stands at 80%. What should you do? Drastically lower your prices to have more ads filling your ad inventory? Absolutely not! This could lead to low-paid ad creations winning the auctions. What you should do, though, is take a deep breath and understand that ad fill rate is a piece of valuable information. Sticking with our example, achieving an 80% ad fill rate with programmatic means that this system can give you 80% coverage, so you have 20% to fill with another monetization method, like direct deals or with the help of another programmatic partner. When monetizing your content, you must always stay open-minded and make wise decisions!

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