Glossary | F | Fill-Rate

What is fill rate?

An app’s fill rate is a percentage value that measures how often an app asked its advertising platform partners for an ad, and how often an ad was successfully delivered back to the app. 

For example, an app might have 100 mobile sessions where it asked for an ad, but only successfully got back ads in half from those requests, giving the app a fill rate of 50 percent. 

An app’s fill rate is an important performance metric, when it’s used in conjunction with other metrics, such as eCPM. 

A 100 percent fill rate is not necessarily a good thing—a high fill rate could suggest that an app is not pricing its ad space competitively, and could be making more money if it raised its pricing floor. 

A lower-than-average fill rate suggests that an app isn’t successfully finding advertiser demand, which could be due to several factors, including the app’s content, its customer demographics, or ad pricing.