The document discusses how marketing should be viewed as a growth engine for companies, especially startups. It outlines five steps to build an effective always-on marketing engine: 1) define the purpose and mission, 2) build integrated marketing components, 3) define success metrics, 4) understand user motivations, and 5) transition from campaigns to always-on engagement. The overall goal of the engine should be to grow the brand, grow the user base, and grow user value through personalized messaging delivered at the right time.