Ethan Donati with his marketing hat on, talks about "stadium logic" which is a 'rule of thumb' prediction device using the concept of a stadium full of people, how many will be ready to "buy in"/respond in your target audience and how many will never "buy in", and how many 'might'?
Based on the total number of Australian's in the age bracket, if 3% are potentially responsive & ready to 'buy in', that means this project is potentially targeting an audience of over 200,000 Australian's in this age group around the country.