The Gatekeeper Dynamic: Updating Lewin's Gatekeeping Theory for the Age of Digital Advertising Ecosystems

This paper introduces the term “Gatekeeper Dynamic” as a modern extension of Kurt Lewin’s Gatekeeping Theory, redefined for the context of digital advertising ecosystems. The concept explains how dominant platforms such as Google retain advertising spend within their own environments by controlling audience attention, data, and measurement tools. This work situates the Gatekeeper Dynamic within the attention economy and digital marketing, using Alphabet’s advertising channels as a case study. It also discusses strategic implications for platforms, advertisers, and policymakers, and how platform ecosystems shape competition, innovation, and advertising strategy.