How Ideas Spread
In 1865, Gregor Mendel published the paper that established him as the father of genetics. However, it went largely unnoticed until it was rediscovered decades later and became widely recognized as one of the great discoveries in the history of science.
Why do some ideas quickly spread far and wide while others go nowhere at all?
Now that we are in the midst of a communication revolution, the problem of understanding how ideas spread has taken on greater significance. Some serious thinking has been done about it and important insights have been gained. It’s worth some time and effort to take a look.
The most obvious place to start is epidemics.
The SIR Model of Epidemics
The standard for studying epidemics is the SIR model, which has been around since 1927. Elaborations have been made since then, but the basic model is still applied not only to biological epidemics, but to computer viruses and communication as well.
The basics are simple and straightforward. The model has three stages: Susceptible, Infections and Recovery.
Susceptible: A susceptible population contributes to an epidemic. If there is poor nutrition, bad environmental factors or genetic predispositions, people are more likely to get sick. Along the same lines, cultural environment contributes to the spread of ideas. A great idea is one whose time has come.
Vaccines, anti-poverty programs and antivirus software are all examples of steps taken to limit susceptible populations.
Infectious: An infectious population transmits the disease. The degree to which it does so depends on both the nature of the disease and the structure of interactions in the population. For example, the Ebola virus is highly contagious, but has mainly been limited to isolated areas so epidemics have never spread very far.
Isolating the affected population and limiting the contagion through good sanitary conditions or medicine are both good strategies to limit infectiousness.
Recovery: Eventually, people get better or they die. When the recovered population begins to grow, the epidemic starts dying out.
The SIR model assumes that epidemics have a life-cycle. First the conditions for an epidemic set the stage and then people get infected. If the infection rate is above one, meaning that people get infected faster than they recover, a tipping point is reached and the epidemic grows, sometimes explosively.
Eventually, the population starts to recover and the epidemic ends. However, that can take a while. The Black Plague epidemic lasted for decades.
The Tipping Point
The Power of Context: Similar to susceptibility in the SIR model, Gladwell gives some examples how environment plays a role in spreading ideas. For instance, he cites the role of cracking down on smaller crimes as a way to prevent bigger ones.
The Stickiness Factor: Just like some diseases are more contagious than others, some ideas hold greater sway over people.
The Power of the Few: Probably the most memorable part of Gladwell’s book is his taxonomy of influential people. For instance, “Mavens” are masters of information, “Connectors” know a lot of people and “Salespeople” are very powerful communicators.
Epidemics in a Networked World
One of the problems with the SIR model is that it doesn’t take into account the structure of populations. However, we know that the make up of a society is important for individual interactions.
Unlike Ebola, AIDS was concentrated in cities and quickly spread to a global pandemic. In the US, people on the coasts are more likely to share ideas with each other than they are with people in the center of the country. Increasingly the connections which spread ideas are not geographical.
An important facet of the structure of any network is that there are not only hubs and clusters, but ways to go around them. We have shortcuts that let us get from point to point more quickly. It is the fact that clusters mix in unpredictably ways that makes social networks work the way that they do. (See here for more about the forces that drive social networks).
The Power of the Many
Seen in the light of network structure, Gladwell’s “Power of the Few” concept begins to break down. Why focus exclusively on convincing a few influential people when there are so many people around them? After all, influential people are connected to many others that may be more open and easier to convince.
In effect, starting an epidemic is similar to a broadcast search. You are better off casting your net as widely as possible and reaching influential people as well as less influential ones. (See this article for more about broadcast and directed network searches)
Some paths will fail, but the more paths you initiate, the more likely that your idea will infect those who are susceptible to it. Just like delays at any airport can affect large hubs, influence can originate anywhere in social networks.
Ideas That Spread Themselves
It has long been known that people are influenced by others around them. Solomon Asch conducted experiments in the 1950’s that showed that people will give answers that they know to be false if every other person in their group gives the wrong answer. The majority doesn’t just rule, it converts.
Viral ideas are the holy grail of marketing. Why spend money on huge advertising campaigns when you can get people to spread your ideas for free? Unfortunately, it is very hard to get things to go viral and nearly impossible to do so with any predictability or consistency.
So you wouldn’t want to risk a major product launch on the slim chance that you might save your advertising budget; there’s too much at stake. Businesses don’t become successful by saving on marketing, they become successful by selling products.
In order for ideas to spread, you have to not only get people to believe in them, but you need a majority of people to believe in them (or at least a local majority).
That’s the problem with Gladwell’s view. He effectively assumes that the “influentials” that make up the “Power of the Few,” will be easier to convince than the masses. Ideas don’t exist in a vacuum, they spread through interactions. By focusing on just one element he excludes important opportunities.
Three Conditions for a Viral Idea
Susceptibility: Either the idea has to be very powerful or people who are predisposed need to come in contact with it. A great idea is one whose time has come!
This has been my experience in the media business. I’ve seen the same product launched the same way in different markets with much different results. A good product always does well eventually, but sometimes it can be an instant hit, and sometimes it takes a while.
Connectedness: The people who believe in the idea have to be able to interact with others. Even the powerful Ebola virus dies out in the African Jungle. Those infected are too far away from population centers to create a widespread epidemic.
Practically, this means you shouldn’t choose a target that is too broad, but also that demographic targeting can be misleading. For instance a young target group doesn’t mean anything unless they are young people who connect with each other.
Majority: Even healthy people can get sick in an epidemic and even skeptical people can be influenced by an idea that permeates their local environment.
Because clusters in a network are connected, they influence each other. It really isn’t all that important which people are influenced initially. One very active cluster can percolate through the entire network. The cluster doesn’t have to be central, just connected strongly enough to allow for interaction.
A majority doesn’t just rule, it convinces. A campaign must be big enough and sustained enough to build a majority in a local network. Once a local network cluster is self sustaining, they can spread the word.
A good example is Facebook, which was first limited to Harvard, then limited to university students and only then was able to conquer the world. If they started out as a social network for the general public, they probably wouldn’t have gained the momentum they needed.
Practical Marketing Implications
Through combining insights from network theory with the SIR model of epidemics, some practical steps can be taken to improve marketing campaigns.
Mass Media: Reaching a lot of people cheaply is the best way to reach the specific people you need. Which would you rather have, a client meeting or a presentation at a conference? At the conference, you will not only reach your prospect but also be able to influence others who can affect her decision.
Don’t Over-Target: Social Search research shows that combining a few general targeting parameters is enough for a message to reach its intended objective. Laser like focus can be less efficient and you lose the chance to reach people who can influence the target. You should build your target to suit your budget, but there’s no reason to exclude people if you don’t have to.
Encourage Word-of-Mouth: Social Media strategies are a great way to extend a marketing campaign, but not a replacement. To get the maximum effect, integration with Mass Media and other marketing communication is crucial.
Duncan Watts calls this idea “Big Seed Marketing.” (For a fuller explanation, see this Fast Company article.)
The new socially networked world offers great opportunities to increase the efficiency and effectiveness of conventional marketing campaigns. However, the old standards of a powerful idea, efficient buying and good integration live on.