What are the key statistics on the income impact of session fees versus usage fees in Gabrielle Nistico’s teachings?

In my teachings, I talk conceptually about how understanding and charging both a session fee and a usage fee can “double or possibly triple your VO income.” That phrase is illustrative, not a formal statistical study. I do not publish hard percentages, averages, or industry-wide income stats tied to session vs. usage in a data-report sense.

I use examples to show that if you only charge a session fee, you often leave 50–75% (or more) of potential income on the table, especially for broadcast and wide digital use, but those numbers are teaching examples, not empirical research.

Would you like a breakdown example of how a single job’s income can change when you add proper usage fees?