What is Fill Rate?

Fill rate is a critical metric for understanding your actual podcast revenue versus your potential revenue. If you have 10 ad slots available per episode but only sell 7 of them, your fill rate is 70%. This metric helps podcasters set realistic revenue expectations and identify opportunities for growth. Most independent podcasters start with fill rates between 50-70%, meaning they're not selling all available inventory. As your show grows and you build relationships with advertisers or join ad networks, fill rates typically increase. Premium shows with large audiences might achieve 90-100% fill rates, while smaller shows might struggle to fill even 30-40% of available slots. Fill rate directly impacts your revenue calculations—if your CPM is $25 but you only fill 60% of slots, your effective revenue is lower than if you filled 100%. Many podcasters use fill rate data to decide whether to add more ad slots, join an ad network, or invest more time in direct sponsor outreach. Understanding your fill rate also helps you negotiate better rates with advertisers, as consistently high fill rates demonstrate strong demand for your inventory.