Measurement
Fill Rate
Fill rate is the share of eligible ad opportunities that result in an ad being served or otherwise counted as filled under the platform's measurement rules.
It helps publishers understand how much available inventory is monetized and can reveal demand, pricing, latency, policy or technical gaps.
How it works
- Measure the eligible or requested ad opportunities.
- Measure the opportunities that produced a filled ad response.
- Divide filled opportunities by eligible opportunities and express the result as a percentage.
Frequently asked questions
Is 100% fill always the best outcome?
Not necessarily. Maximizing fill at any price can reduce yield or quality; publishers usually balance fill, price, user experience and demand quality.
What can reduce fill rate?
Low demand, high floors, targeting constraints, timeouts, policy restrictions, creative rejection and technical errors can all reduce fill.