The document discusses how to create an effective word-of-mouth marketing campaign by disrupting consumers' mental schemas or expectations. It explains that the brain likes to maintain existing schemas to conserve energy. Word-of-mouth is generated when a brand significantly disrupts schemas by surprising consumers in a way that fits the brand's core purpose. Two examples are given of how Kia disrupted expectations of Korean cars and Secret deodorant disrupted assumptions about sweating and smelling. The key is finding the main schemas in a category and creating disruptive messaging that is still consistent with the brand.