# Fill rate

The share of eligible ad requests that return an ad.

The share of eligible ad requests that return an ad.

## An example

If 100 eligible requests return 60 ads, the fill rate is 60%.

## Why it matters

The denominator matters. Requests ruled out before an auction should not be silently mixed with eligible requests.


## Related terms
- [Ad placement](https://jolts.xyz/resources/glossary/ad-placement)
- [No fill](https://jolts.xyz/resources/glossary/no-fill)
- [Publisher](https://jolts.xyz/resources/glossary/publisher)
## Related articles
- [Build a test set where the right ad is no ad](https://jolts.xyz/blog/a-test-set-for-showing-nothing)

## Next step

[Explore advertising](https://jolts.xyz/advertisers) or [monetize your AI app](https://jolts.xyz/publishers).