Fast MMM vs Accurate MMM You shouldn't have to choose. The real question: Did reality agree with the prediction? Out - of - sample validation A Strong Historical Fit Isn't Accuracy Explains the past In - sample fit Real - world validation is the strongest test. Tests unseen periods Real - world prediction track Tests whether recommendations actually worked Experiments Are the Referee That's how marketing mix modeling accuracy improves over time. MMM predicts Geo experiment tests Reality confirms or challenges The result feeds back into the model. Validation Makes Speed More Valuable 12 validated monthly forecasts 1 validated annual forecast More validated predictions Stronger prediction track record Speed compounds accuracy when every refresh is validated. Why Quarterly MMM Can Go Stale A quarterly model can average over shifts it hasn't detected. CPMs change. Auction dynamics change. Platforms change. Faster, validated refreshes compound accuracy. ? ? ? Fast but flimsy Show me your out - of - sample performance. Show me a prediction that was acted on and confirmed. What changes between refreshes? Slow but stale Also ask: When did the model last detect a platform shift? 01 How long does it take to move from data to decision? 02 What happened to accuracy during the last volatile quarter? 03 The real question is whether the model’s predictions hold up in the real world. PrimaryButton3.png Read the full article - >