How Ideas Spread

1. Social Epidemics: Ideas Spread Like Viruses

Products and ideas can spread from person to person, just like viruses.

Contagious ideas. Social epidemics occur when products, ideas, and behaviors spread rapidly through a population, much like a virus. This spread isn't random; it's driven by social influence, where one person's actions impact another's. Examples include the Livestrong wristband craze, the spread of urban legends, and the adoption of recycling.

Beyond quality and advertising. While quality, price, and advertising play a role, they don't fully explain why some things catch on while others fail. Psychological and sociological mechanisms, such as trialability (how easy something is to try), are crucial. For example, satellite radio initially struggled due to high barriers to trial, but once they lowered the bar, it caught on quickly.

Natural selection of culture. Just as natural selection shapes biological traits, it also shapes cultural trends. Ideas that fit with human tendencies, drives, and motivations are more likely to be shared and become successful. This involves variation, selection, and retention, where some ideas are more likely to be remembered and shared than others.

2. Exposure, Perception, and Memory Shape Choices

The more you see something, the more you like it.

Exposure increases awareness and liking. Exposure is the first step in information processing. Simply being exposed to something can increase awareness and liking, a phenomenon known as the mere exposure effect. For example, negative reviews can increase sales for unknown authors because they increase awareness.

Perception is subjective. How we interpret information is influenced by subtle cues. The same wine can be perceived as better if it's labeled as coming from California rather than North Dakota, or if it's believed to be more expensive. Even medical treatments can be affected by the placebo effect, where perceived price influences effectiveness.

Memory is associative. Our memory is organized as a network of interconnected ideas. Marketing communications create desired links in memory, shaping how we behave. For example, the associations we have with brands like Walmart or Target influence our shopping choices. These links act as shortcuts, but they can also be difficult to change.

3. Triggers: Subtle Cues Drive Behavior

Triggers make products and ideas more top of mind, which makes people more likely to choose them.

Triggers activate associations. Triggers are stimuli in the environment that make us think about related concepts or ideas. These triggers can be based on existing associations (like Mars the planet and Mars the candy bar) or new ones (like a white duck and Aflac). They influence what's top of mind, which in turn affects our choices.

Context matters. The context in which we encounter triggers can significantly impact our behavior. For example, voting in a school might lead people to support education funding, and playing French music in a grocery store can increase sales of French wine.

Frequency and timing are key. How often something is triggered influences how frequently it comes to mind. Ideas have "habitats" of triggers that cause people to think about them. The timing of triggers is also crucial; they need to be present when the desired behavior is possible. For example, a bath mat ad is ineffective if it's not seen in the bathroom.

4. Sticky Ideas: Simple, Unexpected, Concrete, Credible

The simpler and easier to understand an idea is, the more likely people are to remember it.

Simplicity is key. Simple ideas are more memorable. Focusing on one or two key ideas is more effective than trying to communicate too much at once. Analogies help make complex ideas simple and memorable. For example, describing Facebook as an online yearbook made it easier to understand.

Unexpectedness grabs attention. Unexpected things are more likely to be remembered. Violating expectations and breaking patterns can make an experience more memorable. The movie The Blair Witch Project was unexpected because it blurred the lines between reality and fiction, creating a curiosity gap.

Concreteness aids visualization. Concrete language makes messages memorable because it helps the listener visualize what is being talked about. For example, describing a construction firm as "building is a series of conversations" is abstract, while "who designs it, arranges it, brings it" is concrete.

Credibility builds trust. Credible messages are more likely to be believed and remembered. Putting numbers in context and using testable credentials can increase credibility. For example, Clinique's "tape test" allows people to convince themselves of the product's effectiveness.

5. Conformity: The Power of Social Imitation

In general, people like to be liked.

Informational influence. People conform to others because they use others' choices as information, especially when they are uncertain. This is called informational influence. For example, if a vacation destination seems popular, we assume it must be worth checking out.

Normative influence. People also conform to fit in and avoid being ostracized. This is called normative influence. The Asch line experiment showed that people will conform to the group even when they know the answer is wrong.

Groupthink and dissent. Conformity can lead to groupthink, where everyone takes the same perspective. However, even one dissenter can free people up to share their true opinions. Conformity often happens below our awareness, and we tend not to see it in our own behavior.

6. Divergence: Signaling Identity Through Choice

People not only care about what things do, but they also care about what they mean.

Signaling identity. People buy things not just for their function but also for what they signal about their identity. Conspicuous consumption is used to signal desired identities. For example, the Honda Element's image shifted as it was adopted by different demographics, leading some to diverge.

Conformity vs. divergence. In functional domains, people tend to conform to what others choose. However, in identity-relevant domains, people diverge to avoid signaling undesired identities. For example, teenagers don't want to look like their parents.

Subtle signals. Wealthy people often prefer subtle signals, like less prominent branding, because they are harder to copy. Explicit signals are easier to identify but also more likely to be pirated. Subtle signals provide a covert communication system with other insiders.

7. Word of Mouth: More Powerful Than Advertising

Word of mouth is more impactful in the spread of ideas than advertising.

Trust and targeting. Word of mouth is more effective than traditional advertising because people trust their friends more and because it's more targeted. Friends are seen as more objective and candid than advertisements.

Different models of communication. Advertising is a broadcast medium driven by marketers, while word of mouth is consumer-driven and about participation. Word of mouth is narrowcasting, integrated into everyday life, and more you-focused. It's also more cost-effective.

Online vs. offline. While online communication has made it faster to share information, most word of mouth still happens offline. We tend to overestimate online word of mouth because it's more visible. The psychology of sharing is more important than the technology.

8. Social Currency: Sharing to Look Good

Just like the car we drive and the clothes we wear, the things we say and the things we share affect how other people see us.

Desired signals. People share things to send desired signals of identity. They share things that make them look good rather than bad. This is called social currency.

Insider status. Making people feel like insiders increases their likelihood of sharing. For example, LinkedIn sent emails to subscribers noting that they had one of the top profiles.

Inner remarkability. Even mundane things can be made remarkable if we think about what makes them surprising, novel, or interesting. Blendtec's videos of blending iPhones made blenders remarkable.

9. Practical Value: Sharing What's Useful

If something is top of mind, it’s much more likely to be tip of tongue.

Useful information. People share practical, useful information to help others, whether it's saving time or money. Links with titles like "10 tips for using your phone more effectively" are often shared.

Framing deals. How deals are framed can impact whether people share them. Percentage discounts are more effective for lower-priced items, while numerical discounts are more effective for higher-priced items. This is known as the rule of 100.

Triggers and top of mind. If something is top of mind, it's more likely to be shared. Even if something is not the most interesting, if we're thinking about it, we're more likely to talk about it. For example, Rebecca Black's song "Friday" is triggered every Friday.

10. Public: Making the Private Visible

If something is easier to see, it’s easier to imitate.

Social proof. People use others' behavior as a signal of information. If a restaurant is full, we assume it must be good. This is called social proof.

Making the private public. To encourage imitation, companies and organizations need to make the private public. For example, Apple made white headphones to make their product more visible.

Backfiring effects. Highlighting what other people are doing can sometimes backfire. Anti-drug campaigns that highlight how many people are using drugs can inadvertently increase drug use.

11. Social Networks: Ties That Bind and Influence

Our social networks are often divided into different spheres of life.

Nodes and ties. Social networks are composed of nodes (people) and ties (connections). The pattern of ties influences how information spreads. Some people are more central in the network, while others are on the periphery.

Small world phenomenon. Milgram's small world study showed that any two people can be connected through about six degrees of separation. However, people don't always know the shortest paths.

Homophily and tie strength. People tend to be friends with others like them (homophily). Strong ties are close relationships, while weak ties are casual relationships. Weak ties are often more useful for accessing new information.

12. Data-Driven Insights: Tracking What Catches On

Social media is not just a marketing platform—it’s also about listening.

Social media monitoring. Companies use social media monitoring to track what people are saying about their brand. They measure volume (how many people are talking about something) and sentiment (whether the comments are positive or negative).

Big data and predictions. Big data can be used to predict trends. For example, Google used search data to predict outbreaks of the flu.

Limitations of data. While data is useful, it's important not to become overly reliant on it. Sometimes, focusing too much on data can lead us astray. It's important to balance data with intuition and qualitative insights.

Last updated: February 2, 2025