Viral marketing is at an early stage of development and much of the current viral
marketing communication (VMC) literature research is concerned with understanding the motivations and behaviours of those passing-on email messages. We believe its growth will depend partly on establishing both suitable criteria and methodologies in order to measure and evaluate the effectiveness of viral campaigns. Borrowing methods from WoM may not necessarily be appropriate and current methods based around hits and impression counts are increasingly criticised by practitioners (Bazadonna, 2006) and discounted by academics.