Does an Idea Spread Like a Virus or a Forest Fire?

4 02 2008

Conventional word-of-mouth wisdom sees information spreading like a virus, infecting the masses through a small group of influential individuals. Bring a few “influentials” on board with your product or idea, the concept goes, and they will spread it for you on their own through their large social networks and natural enthusiasm. 

The virus model itself spread like a virus across the field of marketing. It sits at the heart of popular marketing books such as The Tipping Point and The Anatomy of Buzz, and has spawned a whole new field of marketing, called viral marketing.

But according to network-theory scientist Duncan Watts, the virus model, and especially its reliance on influentials, fails to account for important aspects of how information travels. Influentials may increase the number of people exposed to an idea, but there is little evidence to show they are vital to the start of any trend.

A better model, he suggests, is that of a forest fire. Thousands of fires begin in forests each year, but only a few grow into massive blazes. The key factors that determine whether the fires spread, he said, are environmental – whether the forest is ready to ignite. If the earth is dry and the wind is blowing in a favorable direction, any match could could create a major catastrophe. But the same match dropped on a rainy day would have no effect at all.