Agency economics involves more than negotiating a retainer. It asks who pays for creative and strategic time, what costs an agency carries, which risks it accepts, and how it demonstrates business value to clients and investors. Ivan Fernandes examines how the agency model is shaped by capital, margins and acquisitions. Prasad Sangameshwaran explores the balance of power between procurement, clients and agencies, including whether the industry has trained buyers to expect too much without adequate compensation. Raja Ganapathy explains an alternative in which agency-like capabilities can coexist with an equity-linked investment model, while cautioning that investment is not simply a substitute for payment for services. Mithila Saraf, Shradha Agarwal and Arvind Krishnan contribute practical perspectives on selecting pitches, defining scope, managing cash and matching senior capability to an agreed fee. This hub concerns commercial models; broader organisational leadership and client relationship skills are treated separately.