There is no such thing as a perfect virus or we wouldn’t be here to talk about it.
All networks – including human and server-based ones – operate according to a nearly universal series of fundamental properties. In fact, viral messages propagate throughout the media multiverse in much the same way as the Black Plague clawed its way through Medieval Europe.
Leaving aside our biological counterpart, however, a viral message is based on a remarkable idea. This is an idea that is worth remarking on, that is worth sharing.
Viral messages often employ humour and/or controversy to address issues (sex, religion, ethics, politics, etc.) that generate vast interest and interaction.
In fact, as Seth Godin has pointed out, even a simple unorthodoxy will naturally attract interest as long as it is remarkable:
Cows are a perfectly normal occurrence on the side of the road, you’d never stop to see one, but a purple cow isn’t the norm; in fact, it would be quite astonishing. You might pull over to have a look.