INTRODUCTION
“It’s Amazon.” That was Sir Martin Sorrell’s answer to the question, “What keeps you up at night?” (O’Reilly, 2017). Not Google or Facebook, but the new kid on the advertising block. The former WPP chief executive officer even predicted that Amazon’s advertising budget one day would reach $100 billion—rivaling other walled gardens (Weissbrot, 2018).
Advertising professionals often are reminded that advertising dollars follow eyeballs. Although this is true over the long run, shifts in marketing budgets do lag the evolution of media consumption. Dollars do not reallocate themselves magically according to engagement. Inertia is a powerful force, and budgets...