Not-for-profit organisations seeking to enhance social campaign messages through viral social marketing may find it hard to be edgy enough for success, while conforming to their own values.

That is according to Danya Hodgetts, from Central Queensland University, who has tested viral marketing to send an anti-obesity message.

Viral marketing - otherwise known as ‘word of mouse' - involves creation of a funny or confronting photo, animation or video clip Email, in the hope that those receiving it will pass it on to dozens of friends.

Ms Hodgetts' team found it hard to push the envelope far enough to get significant pass-on success, although their video involving a man walking his dog while watching TV was well received by the initial audience and led to click-throughs to a physical activity website.

"We would have liked to try something much more edgy but we had to remember we were representing an organization with certain value standards," she said.

"Viral marketers are advised to ensure their messages evoke a strong emotion such as humour, fear, sadness or inspiration. In the case of health messages, we hope people will pass them on through a desire to do good."

But Ms Hodgetts said the internet was becoming increasingly cluttered and it would become even harder for campaigns to cut through without being too edgy and making the source organization too nervous.

Danya Hodgetts is the Program Director for Health and Exercise Studies at CQU, based at Rockhampton Campus.