Retail marketing has been optimizing Cost Per Click for two decades. The business has been measured in carts, margin, and retained customer value the entire time. The essays here name the gap and walk through the Retail Decision Stack — the KPI hierarchy that makes sense once AI is the one allocating spend across the funnel.
Universal Cart moves add-to-cart inside Search, YouTube, Gmail, and Gemini — and takes the Retail Decision Stack's ground truth with it. The fix: move it to the order, before the cart finishes moving to Google.
Retail marketing runs on Cost Per Click. The business runs on retained margin per cart. The Retail Decision Stack rewrites the KPI hierarchy for an AI-mediated funnel.