Reading an MMM
Contribution and ROI.
From Coefficients to Decisions
A fitted MMM hands you coefficients, contribution charts, response curves, and fit statistics. Reading them well turns math into budget decisions.
This lesson walks through the outputs an analyst actually scrutinizes before trusting a model.
The Contribution Decomposition
The headline output splits total sales into base and each channel's incremental contribution over the period.
Read it as: of all units sold, how many would have happened anyway (base) and how many each channel added. Sum of parts should reconcile to actual sales.
channel contribution % of sales
base 1,400,000 70.0%
TV 280,000 14.0%
Search 180,000 9.0%
Social 100,000 5.0%
OOH 40,000 2.0%