This document discusses strategies for growing revenue by either doubling the audience through scale or converting more existing audience members into buyers through efficiency. While doubling the audience via scale through advertising is cheaper, doubling the audience via efficiency through sophisticated customer relationship marketing is more difficult. New technologies allow pursuing both strategies by first using data to understand customer motivations and improve efficiency, then applying those insights at scale through algorithms and analytics to acquire new audiences likely to purchase. However, the document cautions that audiences may not scale indefinitely and a balanced approach considering awareness, relationships, and social factors is ultimately needed.