When planning a SMM campaign, it is necessary to show marketers the number of people that are engaged through social networks.
To answer the simple reach question, the lovely people from AllFacebook have created a utility that quickly shows the growth of active (?) users on the Facebook platform.
NZ Facebook reach
Australia Facebook reach
As a percentage of population, Facebook reaches approximately 11% of NZ population (assuming 4.3m people in NZ) and approximately 19% of Australia (assuming pop. 22m).