How it works
If last-click from one platform were enough, every company would already know where to put the next dollar. They don’t — because advertising effects overlap, lag, and saturate. That is what a mix model is built to untangle.
Why this, now
Marketing specialists are asked to grow the business while the measurement they used to trust is getting worse. Privacy changes, walled gardens, and a longer path to purchase all break last-click. Companies still have to set a budget.
Platforms cannot see the whole journey
Cookies, IDs, and in-app tracking no longer stitch people across Google, Meta, retail media, TV, and offline. Each channel still claims the conversion it can see. None of them can see the mix.
Last-click punishes everything that is not the closer
Brand, YouTube, TV, and prospecting look inefficient. Search and retargeting look heroic. Teams then starve the channels that create demand and overfund the ones that harvest it.
Spend is large enough that a wrong mix is material
When advertising is a real line on the P&L, “the dashboard said so” is not a decision. Boards and CFOs ask what incremental sales the mix produced. Last-click cannot answer that.
Diminishing returns are the rule, not the exception
The channel with the highest reported ROAS is often the one already saturated. The next dollar belongs where marginal return is still high — which you only see with a response curve, not a last-click ratio.
Why the model is complex
A marketing mix model (MMM) is statistical, on purpose. It uses your own spend and sales history to estimate what is incremental — instead of trusting each platform’s pixel.
Lag and carry-over
Ads keep working after the impression. If you only credit the week of spend, you misread both efficiency and timing. The model allows effects to persist (adstock) instead of assuming instant last-click.
Channels move together
You rarely run one channel in isolation. MMM estimates contribution while channels, promotions, seasonality, and holidays are all in the data — the situation a specialist actually lives in.
Saturation
Doubling spend does not double sales. The model fits diminishing returns so “put more into the winner” is tested against a curve, not a slogan.
You do not need to run the statistics. You need the output: which channels are pulling their weight, and what the next mix should look like.
What companies get from it
12Fifteen exists so marketing specialists are not stuck between agency last-click, platform ROAS, and a gut feel. The product is the model plus the decision layer: track spend, measure contribution, change the makeup of the budget, and refresh as the plan moves.
Diminishing returns
As spend increases, incremental revenue typically rises — then the marginal return declines. That is why the next dollar is a mix question, not a last-click question.
The process for you
01 — Upload
Marketing spend by channel and sales. Promotions and holidays if you have them.
02 — Model
We estimate incrementality across the mix — lag, saturation, and controls included.
03 — Understand
Contribution, efficiency, and where spend actually went — not platform-reported last-click.
04 — Decide
A recommended mix, a simulator, and a monthly cadence so you keep deciding as spend moves — not a one-time consultant PDF.
You upload marketing and sales data. We treat that as confidential business information and do not share it with third parties. Security, access, and retention are covered in onboarding — we will not overstate certifications we have not listed here.
Launch Access is a monthly subscription — an ongoing relationship, not a one-off project.
Apply for Launch Access$1,299/month $299/month launch cohort