Marketing Mix Models Face Reckoning as AI Promises Real-Time Accountability

For decades, marketers have relied on MMMs as a blunt instrument to connect spending to outcomes, but the models are notoriously laggy and depend on historical data that misses how consumer behavior shifts in real time. AI tools are now enabling direct attribution, which threatens the comfortable ambiguity that has allowed agencies and brands to justify budgets without proving impact. Accountability that actually works forces harder choices about which channels and campaigns to fund, and which to cut.