Every marketer knows their attribution is broken. Last-click is dead, multi-touch models contradict each other, and now vendors promise AI agents will magically solve it. They won't. This session unpacks why attribution remains the single hardest unsolved problem in digital marketing, why throwing agents at it actually makes it worse, and what works instead. Using Unilever/Oswald & flaschenpost as a live case study, we show how a regression-based, privacy-safe approach outperformed custom-built ML models and delivered a 13% sales uplift by finally answering the question: "Where should my next pound go?" Interactive element: bring your own attribution setup. We'll run a live diagnostic with the room, mapping common attribution architectures to their blind spots. You'll leave with a framework to audit your own attribution and a realistic view of what AI can and cannot do for your budget decisions today.