Know where your next dollar should go.
Map how each channel responds to spend, calibrated with experiments as you run them.
Included in every plan, free and up. No credit card.
Illustrative.
Trusted by growth teams who left enterprise measurement vendors
Any model can give you an answer.
The question is whether it predicts, and whether anyone acts on it.
Build it. Check it. Anchor it. Use it.
Try the move before you make it.
Change the budget and see how expected incremental return changes.
Illustrative.
Your experiments keep it grounded.
A model shows what could happen; your holdouts anchor it to what actually did.
With Stella, you know.
Which channels are overallocated.
Where the last dollar is already past the bend.
Which are underfunded.
Where the same dollar would return more.
How much a channel can absorb.
Before returns start to flatten.
What a different budget returns.
Modeled before you commit it.
What wasn’t marketing.
Promos, price changes and out-of-stocks, separated from media.
Whether to trust the model.
Out-of-sample validation, shown on every run.
Ask Stella about MMM.
Whether your model will predict, what the validation means, and where to reallocate.
Hear it from the brands we run measurement for.
Media mix modeling questions, answered.
Is this just Meridian or PyMC under the hood?
No. Stella’s MMM is a custom model built in-house, not Meridian or PyMC-Marketing under a new skin. The practical difference is calibration: you can add holdout results as anchors, each tied to a timestamp and a spend level, and the response curves adjust around that causal evidence. Every model ships with its out-of-sample validation so you can check it yourself.
What makes a media mix model accurate?
A model is only as good as its predictions on data it has not seen. Stella reports out-of-sample MAPE, R² and VIF on every model, and supports forward and back testing, so you can confirm the model predicts before you reallocate budget on it. A confident-looking result is not the same as an accurate one.
How much history does the model use?
Around 27 months where available: two full years plus a rolling quarter. Two full years is what it takes to be honest about seasonality; the rolling quarter keeps the model current. Shorter histories still work, with wider uncertainty.
Why are your confidence bands wider than my dashboard’s?
Because they should be. A model estimated over two years of real data carries real uncertainty, and hiding it does not remove it. Stella shows the band, and narrows it the honest way: with holdout evidence at the spend levels you actually tested.
Can I model on spend or impressions?
Both. Model on spend or on impressions, add as many control columns as you need (promotions, pricing, out-of-stocks, weather, seasonality), and tune saturation and ad-stock for longer lead cycles.
What plan includes media mix modeling?
Every plan, free and up. Free includes one model a year on data you upload. From Professional ($3,000/mo) models run straight off your connected data, with unlimited runs. If you would rather not run it yourself, our measurement team will, on a custom-priced engagement.
A real data-science tool. Or we run it for you.
Build a model on your own data, free. Or our measurement team runs it on a custom-priced engagement.