Reach to grab revenue

Ad Fill Rate: A Comprehensive Guide

As a publisher, advertising is most likely your principal source of income. However, in today’s digital market, ad revenues are highly competitive. According to a Siteefy report, 175 new websites are launched every minute, making it more difficult to compete for a piece of the advertising pie. The “ad fill rate” is one metric that can help you determine how well your advertising efforts are working.

Understanding Ad Fill Rate

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The percentage of ad impressions delivered efficiently on a website or app is represented by the ad fill rate. It enables publishers like you to make better decisions in order to maximize advertising opportunities and earn more money.

High Ad Fill Rate vs. Low Ad Fill Rate

– High Ad Fill Rate: This indicates that advertisements are satisfying a significant portion of ad requests.

– Low Ad Fill Rate: This indicates that only a small percentage of ad requests are met with advertisements.

Calculating Ad Fill Rate

The computation of the ad fill rate is straightforward. It is calculated by dividing the number of advertisements provided by the number of advertisement requests and multiplying the result by 100.

For example, if your website is capable of serving 200,000 impressions per day but only serves 175,000, your ad fill rate is 87.5%.

Why Isn’t My Ad Fill Rate 100%?

Technical Errors

Technical problems with your website might have a big impact on your ad fill rate. Ad distribution might be hampered by latency, insufficient demand, and compatibility difficulties (mobile/device/browser).

Page Latency

The speed with which a page loads is critical. If your webpage takes too long to load, the ad server may be unable to fill the ad space in a timely manner, resulting in a lower ad fill rate.


Advertisements may not appear consistently in all browsers, devices, or operating systems. Because many advertisers target mobile users, ensuring that your advertising runs appropriately on mobile devices is very critical.

How to Improve Ad Fill Rate?

  • Work on Website/Page Load Time

Every second counts, especially for ad impressions. Ensuring your website loads quickly can significantly improve your ad fill rate.

  • Get Started with Header Bidding

Old-school methods like daisy-chaining are becoming obsolete. Header bidding can offer better CPMs and is more automated.

  • Go for Location-Based Targeting

Targeting users based on their geography can increase traffic and, consequently, ad calls leading to more impressions.

  • Switch Ad Sizes When Required

Having the flexibility to change ad sizes can help fulfill demand and achieve a better ad fill rate.

  • Deal with ad-blocking

Ad blockers can block ad networks, preventing your ads from being displayed. Solutions like Pagefair and ad block recovery can help recover some impressions and revenue.

What is the Average Industry Ad Fill Rate?

Ad networks typically promise ad fill rates between 25-55%. Larger networks like AdSense can potentially scale your ad fill rate up to 100%.

Does a 100% Ad Fill Rate Imply 100% Potential Revenue?

Not necessarily. While a 100% ad fill rate might seem like the ultimate goal, it doesn’t always translate to higher CPMs. Publishers sometimes have to compromise CPMs to keep ad placements filled, leading to lower revenue per impression.

How to Optimize Ad Fill Rate (Whether 100% or Less)?

Google’s ad balance’ feature allows publishers to control the percentage of ads displayed. This ensures only the highest-yielding ads are shown, optimizing monetization and improving site experience.


Publishers should focus not just on increasing their ad fill rate but also on targeting strategies, ad placement, and website improvements. The goal should be to provide a great user experience, attract quality advertisers, and optimize ad network performance for better revenue.

Frequently Asked Questions

Q1. What exactly is an ad fill rate?

Ad fill rate represents how many of your ad units were served out of all the ad requests sent to an ad server.

Q2. What is a good fill rate?

Generally, companies maintain a fill rate of about 85%-95%. Ideally, you should aim for a fill rate between 97% and 99%.

Q3. What is a programmatic fill rate?

Programmatic fill rate is calculated by dividing the number of ad impressions served by the number of times an ad is requested from the ad networks you use.