The document discusses the rise of voice search and how it will impact digital marketing. It notes that by 2020, 50% of searches are expected to be voice-based. Voice searches tend to be longer and users only hear the top result, making featured snippets and structured data especially important. The document also covers challenges with voice recognition and how speech interfaces are expanding from screens to other devices like watches and cars. Marketers need to optimize for voice by identifying long voice queries and learning about conversation design.