Publisher Monetization

Fill Rate — Definition & Explanation

The percentage of ad requests that result in a served ad impression. Fill Rate = (Filled Impressions / Total Ad Requests) × 100. A fill rate below 95% may indicate overly aggressive floor prices or insufficient demand.

How Fill Rate Works

Fill rate is determined by whether any demand source submits a bid meeting or exceeding the floor price. Low fill rates typically result from high floors, limited demand coverage for specific traffic segments, or technical integration issues.

Why Fill Rate Matters for Publishers

Fill rate directly affects revenue. Even 5% unfilled inventory represents significant lost revenue. Stellor Media optimizes demand coverage to maintain 95%+ fill rates across publisher inventory.

Frequently Asked Questions

What is a good fill rate?

95%+ is the target for most publishers. Some traffic segments (very specific geos, specific device types) may have lower fill rates due to limited demand.

How does Stellor Media achieve high fill rates?

Stellor's 50+ demand partners provide broad coverage across geographies, devices, and content categories, ensuring competitive bidding on virtually every impression.

Should I sacrifice fill rate for higher CPMs?

Setting floors too high reduces fill rate and may reduce overall revenue. Dynamic floor pricing finds the optimal balance between CPM and fill rate.

Related Terms

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