Non and heavy users pretty balanced out. Ain't Mother Nature wonderful?
What percentage of Australians really use social media? This comes from a survey by Sensis whose business (unwanted telephone directories) has been decimated by the web.
As you see on the left left, a third of people surveyed claim to not use social media. This group is more or less equalled by those who use it once daily or more often.
Sensis also reports that the web is getting greyer. Thus, your organisation has less excuse not to get its online act together. Build it and they will come; if a little slowly and carrying cups of tea.