Fill Rate percentage is the ratio of paid to served impressions

Fill Rate, represented as a percentage, is the ratio of paid to served impressions across a Publisher’s website for a given period of time. The Fill rate formula is represented by ;

(Paid impressions / Total impressions served) x 100 = Fill rate %


Your website had 500,000 total impressions or “ad calls” for a given period sent to Gourmet Ads. Only 475,000 of those impressions returned a paid advertisement:

(485,000 / 500,000 ) x 100 = 97% fill rate

From an ad trafficking perspective, we do offer all Publishers 100% fill across your website’s inventory, however most Publishers will consistently see between 97% to 99% fill in the Gourmet Ads Publisher Console. Most ad networks will not disclose this reality.

When an ad is not served we will automatically attempt to serve a PSA (Public Service Announcement), house ad, or, if unsuccessful, will serve a blank. It is in our best interest to serve as many paid ads as possible for Publishers.

Here are just some of the likely scenarios why Publishers do not see 100% fill rate;

  • No Campaigns in a Non-Core Country
    Outside of our core counties of the US, Canada, UK, Australia, United Kingdom or New Zealand, it’s highly possible that in a country like Brazil, Gourmet Ads may not have any campaigns running. In this case we try to fill it with various methods, but this might prove unsuccessful.
  • Network Latency – Slow Ad Calls
    Although our Ad server is hosted in top tier hosting at multiple locations around the world, fast internet connections can commonly become slow and congested. Because our ad server makes an ad serving decision in just milliseconds if there is a slow connection anywhere in the ad call this can impede the delivery of the actual ad from the advertiser’s ad server through our ad server and back to your website. The ad call will time out and we don’t serve a paid ad on your site.
  • User is on Non-Popular Mobile Device
    As mobile starts to increase in popularity, fill rates for Apple iOS and Android devices are quite high, while Windows Mobile, Blackberry, Palm OS and Symbian are lower.
  • Browser-Based Ad Blockers
    For users that have installed web browser-based ad blockers, it’s common when a web page loads for the web browser to still make an ad call ( ie: fire our ad tags) but, when the advertisement tries to serve on the page the ad is blocked, thus serving a blank.
  • User’s Browser in Anonymous Mode (Incognito Mode)
    Many advertisers these days using some kind of cookies as part of the ad serving process from either a targeting perspective, impression capping or a fraud protection method. As a result, when the browser session is cookieless, this significantly reduces the pool of advertisers we can serve, thus causing the issue that we might not fill 100% when viewers are browsing the internet anonymously.
  • Visitor Leaves Before Ads Serve
    Some viewers will quickly visit a site and if they don’t see what they are looking for will leave by hitting the back button or closing the browser before the ad can serve. The ad call was made but not fulfilled, resulting in lower fill.
  • Floor Price Not Met
    For Publishers that have floor prices set up, a much lower fill rate than 100% is expected, as a result of Gourmet Ads redirecting your ad call to your preferred third party or house ad.