The document discusses the evolution of digital advertising from traditional direct negotiations between advertisers/agencies and publishers to modern programmatic buying. It explains how ad networks aggregated inventory but lacked relevance and transparency. This led to the rise of programmatic buying using real-time bidding (RTB) to automate media buying/selling. RTB allows targeting ads to the right users at the right time. The document outlines key RTB terminology and challenges, and how agencies addressed changes through trading desks. It provides an overview of AMNET as an agency trading desk, how it uses data for audience insights and cross-device targeting to meet goals efficiently at scale across premium inventory.