For a hundred years, marketing has focused on persuading the human shopper. But what happens when the shopper is no longer human? This article uses the classic "Dog Food Dilemma" to introduce the Shopper Schism (Great Decoupling)—the irreversible, AI-driven split between the human consumer and the transactional shopper. It deconstructs why our entire commercial playbook is becoming obsolete and what leaders must do to prepare for the age of the Algorithmic Shopper.