Contagious: Why Things Catch On

Berger illustrates his principles of viral marketing through the story of Vietnamese nail salons in America, using this phenomenon as a launching point to explain how ideas and practices spread through society. The narrative begins in 1975 at Hope Village, a refugee camp near Sacramento, California, that housed Vietnamese individuals who had fled their country after Saigon, the capital of South Vietnam, fell to North Vietnamese forces.

The transformation of the nail salon industry originated with actress Tippi Hedren’s interaction with 20 female refugees at Hope Village. These women, many of whom had worked as teachers, business owners, and government officials in Vietnam, found themselves starting over in America with limited employment options due to their inability to speak English fluently. After the refugees noticed and admired Hedren’s professionally manicured nails, they expressed interest in learning the craft. Hedren responded by arranging for her personal manicurist to provide nail care instruction and securing free beauty school education for the group. One refugee in particular, Thuan Le, who had previously worked as a high school teacher in Vietnam, became instrumental in establishing this new business opportunity.

The initial group of Vietnamese women, despite facing significant challenges such as intense competition and low initial demand for manicure services, persevered in the nail care industry. Their dedication and willingness to accept difficult working conditions, including long hours and less desirable locations, enabled them to establish successful businesses. As news of their achievements spread throughout the Vietnamese American community, more immigrants entered the profession. This pattern of success and emulation led to the current landscape of the nail care industry, in which Vietnamese Americans constitute approximately 80 percent of California’s manicurists and over 40 percent of nail technicians across the United States.

Berger employs this case study to demonstrate a broader pattern of immigrant entrepreneurship in American history. He notes similar phenomena of business sector concentration among immigrant groups: Cambodian Americans’ ownership of the majority of donut shops in Los Angeles, Korean Americans’ predominance in New York City’s dry-cleaning industry, Irish immigrants’ control of Boston’s liquor stores during the 1850s, and Jewish Americans’ significant presence in men’s clothing manufacturing during the early 20th century.

Building on these examples, Berger summarizes his framework for understanding why certain ideas and practices become “contagious,” or spread rapidly through social networks. He reviews the six key principles that drive social transmission: Social Currency (sharing information or products that enhance one’s image in the eyes of others), Triggers (environmental cues and associations that prompt people to think and talk about specific products or ideas), Emotion (content that generates strong feelings in people), Public (behaviors and ideas that can be easily observed and imitated by others), Practical Value (useful information that benefits people in their daily lives), and Stories (compelling narratives that carry messages and encourage sharing).

Berger demonstrates how these principles manifest in various successful marketing campaigns. He references examples mentioned in previous chapters of the book, such as the $100 cheesesteak, which generated social currency through its unusually high price point and luxury status; Rebecca Black’s song, which benefited from its title serving as a regular reminder on a specific day of the week; Susan Boyle’s television performance, which evoked strong emotional responses from viewers; and the Movember campaign, which transformed private men’s health concerns into public discussion by encouraging participants to grow visible mustaches during November.

The epilogue concludes with practical guidance for readers seeking to apply these principles to their products or ideas. Berger emphasizes that implementing these strategies requires careful thought and sustained effort rather than substantial financial resources or social media following. He provides a detailed checklist for evaluating products or ideas against each principle, encouraging readers to consider questions such as whether their concept makes people appear knowledgeable or trendy when sharing it, what elements of the environment might trigger thoughts about it, and how it might become part of larger narratives that people naturally want to share.

To illustrate the practical application of his framework, Berger returns to the example of Howard Wein’s $100 cheesesteak promotion. This case study demonstrates how multiple principles can work together effectively: The unusual price point created social currency by giving customers something extraordinary to discuss, the high quality of the product aligned with the restaurant’s luxury brand positioning provided practical value, and Philadelphia’s strong cultural association with cheesesteaks served as a persistent trigger for word-of-mouth marketing.

Berger reinforces his central argument that viral success is not a matter of chance but results from specific, identifiable factors that can be strategically implemented. He presents his six principles as a systematic approach to creating contagious content, arguing that understanding and implementing these elements can help any individual or organization increase their likelihood of achieving widespread social transmission of their ideas or products.