Advertising AI agent · MMM & incrementality

Marketing-Mix Modelling & Incrementality AI Agent

Assemble the spend and outcome series, fit and refit the model, design the geo or holdout experiment that tests it, and turn the result into a budget recommendation the analyst accepts, interval attached.

Typical delivery
4–6 weeks
Deployment
Your stack
Analyst approval
Pre-decision
After launch
Agent Care

What this agent does

Models the spend, not the decision to move it

In

  1. 01

    Spend and outcome series arrive from ad platforms, the CRM and finance systems.

  2. 02

    Series are aligned to one calendar, one currency and one channel taxonomy.

Reason

  1. 03

    The model is fit and refit against the aligned series, one channel at a time.

  2. 04

    Each channel's prior is logged with its source — an experiment, an assumption or a default.

  3. 05

    A geo or holdout test is designed with its minimum detectable effect and power agreed first.

Decide

  1. 06

    The model's estimate is checked against the experiment, and any gap is surfaced, not resolved.

  2. 07

    Every recommendation is routed to the named analyst before a number leaves the model.

Out

  1. 08

    The specification, the priors, the experiment and every edit are retained against the run.

  2. 09

    Execute write actions only inside the approval boundaries agreed during implementation.

Product statement

The agent fits the model and reads the experiment; the analyst decides which specification to accept, and no modelled figure leaves the page without its interval.

Example workflow

One channel estimate, series to approval

  1. 1Series receivedSpend and outcome series, a new experiment result or a scheduled refit
  2. 2Inputs assembledHistoric series, the prior log, calibration history and channel taxonomy, each with its source
  3. 3Estimate draftedChannel contributions, credible intervals, experiment status and confidence
  4. 4Controls appliedSpecification checks, prior-source checks, calibration-gap checks and confidence threshold

No human action required

Stages 1 to 4 run unaided, and no figure is recommended at any of them — the agent is modelling, and the analyst's lane opens at the confidence gate.

5DecisionBranches at the confidence threshold
High confidence

Goes to the analyst to approve.

Low confidence

Adds a second modeller review first.

Analyst approval

The estimate is held with its interval, its calibration status and the confidence.

Approve · Revise · Escalate

Approved — released to planning

  1. 6Reporting systems updatedOnly where write access and approval policy allow it
  2. 7Outcome evaluatedInterval accuracy, calibration gap, edits and post-decision corrections

Edits

Every analyst edit is counted in the evaluation.

What should not run autonomously

Human approval stays in control

Outside the boundary — human approval required

8 items

  • Reallocating budget between channels.
    • Publishing a modelled figure to the market.
    • Setting a channel's ROI prior on its own.
    • Declaring a test result before it is powered.
  • Automation boundary

    Agent acts unaided

    • ✓Assemble the spend and outcome series and fit the model.
    • ✓Design the geo or holdout experiment and its power.
    • ✓Attribute each channel's interval to its prior and source for the named owner.
    • ✓Flag the gap when the model and the experiment disagree, and hold it for the analyst.

    Any output leaves the model only inside the boundaries agreed at implementation, never as fact.

    • Presenting a modelled return as revenue already earned.
    • Reconciling attribution, incrementality and MMM into one figure.
    • Approving the budget shift the recommendation implies.
  • Changes to specification, priors or calibration rules.

Example output

One estimate, annotated

Everything the agent produces is attached to the run it was drawn from.

MMM output · single channel

Illustrative example
Channel
Brand search, always-on
Finding
Large modelled contribution, no calibrating holdout run
Estimate status
Interval untested
Model run
This quarter's model run
Confidence
68%
Attribution
Analyst name on file

As received

Taken from this quarter's model run and the series behind it — nothing on this side is asserted as fact by the agent.

Inputs checked

  • Spend and KPI series
  • Prior source logged
  • Holdout test status

Why it's flagged

The contribution is real in the model and a person still decides.

What the score decides

Below the configured threshold the flag picks up a second modeller review before it.

Action

ApproveReviseEscalate

Value

Where AI adds value

The same four claims, placed at the point in the workflow where each one applies.

Where the value lands

Value 01 – 04

Every channel

From the assembled series

03Modelling

Fit against the series

Draw on the assembled series, the logged priors and the calibration history.

01Approved path

A model is not a measurement

Brand search and retargeting are the classic case: an observational read can show a strong return while a controlled test shows the outcome would have happened anyway — what the experiment exists to catch.

02Human review

Label the question each number

Attribution, incrementality and MMM measure different things; every output states which one produced it, and the three are never blended into a single figure.

04

Build an evidence trail

The estimate, the interval around it and the analyst who accepted it stay on the plan.

Integrations

Typical integrations

Five system groups connect to the same agent. Which of them are in scope is decided in discovery.

  • Media & spend platforms

    • Google Ads
    • Meta Ads
    • TikTok
    • Amazon Ads
    • DV360
  • Business & finance data

    • ERP
    • POS systems
    • Revenue and conversion feeds
  • Modelling tooling

    • Meridian
    • Robyn
    • Custom Bayesian MMM stacks

Agent

Marketing-mix modelling & incrementality

  • Fits the model
  • Designs the test
  • Holds for the analyst
  • Experimentation & warehouse

    • GeoLift
    • Meridian GeoX
    • BigQuery
    • Snowflake
  • Observability & evaluation

    • OpenTelemetry
    • Langfuse
    • Supported monitoring/evaluation sources

Integration availability depends on the client's existing systems and API access.

Agent controls

Six layers between the model and the plan

Every control wraps the one within it. What the set does not catch is named in the map below.

L6 · Outermost — last line of defence

Inward → L1 · closest to the model

L6Rollback / safe modeRevert to descriptive reporting when evaluation or production signals degrade.Roll back
L5Version monitoringTrack model, spec, prior and calibration changes.Track
L4TraceabilityRecord the series, the specification, the priors and the analyst's decision.Record
L3Analyst approvalHold the recommendation for the named analyst; it governs release, not whether the model is right.Gate
L2Policy guardrailsTest every run against configured prior-source and specification rules; a failure returns it.Restrict
L1Confidence thresholdsRoute low-confidence estimates to a second modeller review.Require review
Model coreEstimate produced — channel contributions, credible intervals, calibration status and confidence
L1 – L2
Test whether an estimate may stand
L3
Puts the release in the analyst's hands
L4 – L5
Keep the estimate and the interval behind it
L6
Reverts to descriptive reporting when signals degrade

How Nestack evaluates it

Evaluate the modelling workflow — not only the final number.

Coverage runs the whole depth of the workflow, and every layer is cut by slice.

Surface — the number the analyst sees

  1. E1Final-output evaluationDid the channel estimate ship with its credible interval?
  2. E2Step-level evaluationDid the agent use the current series, priors and calibration record?
  3. E3Tool evaluationDid it read the correct series version and channel ID?
  4. E4Confidence calibrationDo low-confidence estimates actually diverge more from the experiment?
  5. E5Slice evaluationHow does interval width change across specific channel types?
  6. E6Business outcomeHow many estimates needed an analyst edit or a later correction?

Floor — the outcome the plan answers for

Failure modes

Where each failure originates in the agent

Seven failure modes, placed at the stage each one originates.

Agent lifecycle

Direction of processing →

  1. 01 · Retrieval

    1 mode

    • MM-03

      Stale series pull

      The spend or outcome series read is a cached pull, not this period's data.

    Stage gathers

    Spend and outcome series, priors and calibration history

  2. 02 · Reasoning

    2 modes

    • MM-04

      Prior source blurred

      A default or assumed prior is shown as if an experiment set it.

    • MM-06

      Mismatched calibration basis

      An experiment's window or population doesn't match the model's, but calibrates it anyway.

    Stage proposes

    Channel estimates, intervals and confidence

  3. 03 · Tool / write

    2 modes

    • MM-02

      Low-confidence release

      A recommendation reaches the analyst ahead of its confidence gate.

    • MM-05

      Modelled return shown as real

      A modelled contribution is presented as revenue already delivered.

    Stage writes

    Only where write access and approval policy allow it

  4. 04 · Output

    1 mode

    • MM-01

      Interval dropped

      A channel estimate reaches the analyst with no credible interval attached.

    Stage returns

    The estimate the analyst approves

  5. 05 · Change / Version

    1 mode

    • MM-07

      Silent specification drift

      A prior, adstock or specification change widens what the agent will report as fitted.

    Stage tracks

    Model, priors, specification and calibration version

  • Sev-1 · plan acted on outside the boundary
  • Sev-2 · a wrong estimate reaches the analyst
  • Sev-3 · series degrades, run routes to review
See the complete Advertising failure-mode catalogue

Affected slices

One channel can carry most of the risk

A single model fit assigns every channel one number; some channels move far more than others when the specification changes. Nestack reports estimate instability by channel, not only in aggregate.

Slice performance — reported separately, not only in aggregate

Illustrative example
SliceFailure rateLiftLift vs. thresholdStatus
Channels with little spend variation7.5%3.9×Review
Brand search and retargeting5.7%3.0×Review
Channels changed mid-period3.3%1.7×Watch
Large channels with varied spend1.9%0.7×Normal

Bar: estimate-instability lift vs. the large-varied-spend baseline · scale 0–4.0× · tick marks the 2.0× review threshold

2 of 4 slices over threshold

Evidence-linked improvement

The loop closes on a case, not a story

The loop shuts when the wrong estimate is a regression case, not when it has been explained. That suite is what the next model run is measured against.

Improvement cycle · five stages

Switchback — the path turns at Improve and returns at Learn

  1. 01

    Detect

    Interval width or edit rate rises in a channel slice.

  2. 02

    Diagnose

    The point estimate everyone quoted is checked against the series, the priors and the specification until one cause explains the swing.

  3. 03

    Improve

    Whatever changes ships against a version, with the runs that prompted it attached.

  4. 04

    Verify

    Nothing ships until the affected specification cases pass a second time.

  5. 05

    Learn

    The suite grows by one case; so does the calibration record.

  6. Learn → Detect

    The return edge. The next run starts against a suite one case longer.

Typical build scope

Twelve workstreams across six weeks

The build scope read against the delivery timeline. Week structure follows the six-week plan — discovery, sources, modelling workflow, evaluation, integration, then production validation and handover.

Workstream

Week 1Week 2Week 3Week 4Week 5Week 6

  1. 01Analytics discovery and boundary scoping and boundary definition.Week 1
  2. 02Media, KPI and warehouse source assessment.Week 1, Week 2
  3. 03Prior-source and calibration rule mapping and rule mapping.Week 1, Week 2
  4. 04Series ingestion and taxonomy mapping.Week 2
  5. 05Model-fitting logic and interval binding.Week 2, Week 3
  6. 06Confidence scoring and gap routing.Week 3
  7. 07Analyst approval workflow.Week 3, Week 4
  8. 08Warehouse and experiment-tool integration.Week 5
  9. 09Specification and prior cases.Week 4, Week 5
  10. 10Guardrails and acceptance controls.Week 4
  11. 11Run-trail instrumentation.Week 5, Week 6
  12. 12Deployment, documentation and Agent Care handover.Week 6

12 workstreams · 6 weeks · bar shows the weeks a workstream is active — several run in parallel

Final scope and sequence confirmed in discovery

Engagement tiers

What each tier includes

Rows are the capabilities named in each tier's scope. Higher tiers include everything below them.

Capability✓ in scope · — not at this tierPilotOne channel, one marketProductionProduction data and warehouse accessAdvancedMultiple markets / brands
Introduced at Pilot
Model fit to your data✓✓✓
Analyst approval✓✓✓
Calibration baseline✓✓✓
Introduced at Production
Reporting by channel—✓✓
Escalation workflow in your tools—✓✓
Approved output actions—✓✓
Warehouse integration—✓✓
Introduced at Advanced
Multi-market calibration rules——✓
Multi-stage analyst approvals——✓
High channel volume——✓
Multi-market model controls——✓
Build priceFrom $5,000From $8,000Custom quote
Final build price
Confirmed after discovery based on integrations, workflow complexity, transaction volume, approval controls and deployment requirements.
Separate from build
Build pricing is separate from recurring Agent Care, which covers managed monitoring, evaluations, incidents and verified improvements after launch.

What we need from you

What you bring, and what we build with it

Each input maps to a piece of build scope and a week in the delivery timeline.

  1. 01Your spend, KPI and warehouse access

    Series ingestion and taxonomy mapping

    Week 1
  2. 02Representative historical series and any past tests

    Model-fitting baseline and interval attribution

    Week 2
  3. 03Your prior-source and calibration rules

    Prior-source and calibration-boundary mapping

    Week 1
  4. 04Access to relevant APIs, feeds or exports

    Media, KPI and warehouse assessment, then integration setup

    Week 2
  5. 05Estimates you would not want budgeted on

    Experiment cases and failure-mode testing

    Week 4
  6. 06What no estimate may be read as

    Confidence scoring, gap routing, guardrails and approval controls

    Week 3
  7. 07Named analysts to review recommendations

    Analyst approval workflow, then pilot and production validation

    Weeks 5–6

Nothing else is required

Deployment, documentation and Agent Care handover are ours.

Delivery timeline

Four phases across six weeks

Bands follow the real work rather than the plan, which is why evaluation and pilot share week 5.

Phase

W1

W2

W3

W4

W5

W6

  1. DiscoveryW1
  2. BuildW2 – W3
  3. EvaluateW4 – W5
  4. Pilot & LaunchW5 – W6

Week focus

W1Analytics discovery, calibration mapping and the boundary

W2Source integration and the model-fitting baseline

W3Modelling workflow, confidence logic and approval controls

W4Evaluation suite, guardrails and failure-mode testing

W5Warehouse integration, pilot runs and targeted corrections

W6One planning cycle modelled under the analytics lead, then handover

Reading the band
A bar covers only the weeks its work is named in — the week 5 overlap is real, not padding.
At the end of W6
Once the cycle validates, Agent Care owns the running agent.
Duration
Six-week plan shown · typical delivery 4–6 weeks depending on scope confirmed in discovery.

Next step · Advertising AI agent

Build a marketing-mix agent around your measurement stack.

Show us your spend and outcome data, your prior sources and who signs off on a number. The judgement that turns an experiment into a calibrated prior stays with the analyst, not the agent.

Typical delivery
4–6 weeks
Deployment
Your spend and KPI data
Analyst approval
Pre-decision
After launch
Agent Care available

Nestack Agents · Marketing-mix modelling & incrementality

AGT-AM-15 · Agent Care available after launch

Build a marketing-mix agent

Four questions so the call starts from your actual setup — then pick a time that suits you.

About you
Your channels

No obligation. We’ll map the workflow, name the automation boundary and tell you if an agent is the wrong answer.