Who does L&Y Decision work with?

L&Y Decision works with e-commerce brands, DTC companies, and retail businesses — typically with revenues between $500K and $50M — who are serious about making evidence-based marketing decisions. They specialise in small and medium businesses ready to graduate from gut feeling.

What data access does L&Y Decision need to get started?

Read-only access to ad platforms (Meta Ads, Google Ads), analytics (GA4 or equivalent), and commerce data (Shopify, WooCommerce, etc.). L&Y Decision never touches campaign settings, budgets, or creative.

How quickly will e-commerce brands see results from decision science?

Most engagements deliver initial insights and recommendations within 2–4 weeks. Implementation of those recommendations typically produces measurable impact within 60–90 days. Causal inference and attribution model projects take 4–8 weeks by design.

Do you need an in-house data team for marketing attribution modeling?

No. L&Y Decision handles data extraction, transformation, and modeling entirely. If you can grant read access to your platforms, they do the rest. Many clients have no dedicated data function at all.

What is causal inference in marketing?

Causal inference in marketing is a statistical method that isolates the true incremental impact of advertising — measuring what would have happened without the ads (the counterfactual). Unlike correlation-based attribution, causal methods such as geo-holdout experiments, difference-in-differences, and Bayesian structural time-series prove that ads caused revenue, not merely correlated with it.

What is marketing mix modeling (MMM)?

Marketing mix modeling (MMM) is a statistical technique that quantifies how each marketing channel — paid search, social, email, TV, out-of-home — contributes to sales. Unlike last-click attribution, MMM uses aggregate time-series data to measure true channel contribution, accounting for external factors like seasonality and price changes.

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Most Rigorous

Measure true ad impact — not correlation

The most rigorous approach to ad measurement: geo-holdout experiments, synthetic controls, and Bayesian causal models that isolate exactly what your advertising is actually causing.

Book a Consultation

Investment:$8,000 – $25,000

6–10 weeks

Engagement timeline

Causal

Not correlation

Gold standard

Methodology

Deliverables

What you get

Geo-holdout experiment design and implementation

Synthetic control or difference-in-differences analysis

Bayesian causal inference model for ongoing measurement

Incrementality estimates per channel with confidence bounds

Media mix model with causal validation layer

Ongoing incrementality monitoring framework

Investment

$8,000 – $25,000

Fixed project scope

Timeline

6–10 weeks

Book a Consultation

Process

How it works

Experiment Design

We design geo-holdout experiments or synthetic control studies — the gold standard for causal ad measurement. This involves selecting test and control markets and setting up proper randomisation.

Data Collection

We monitor the experiment in real time to ensure data quality, check for contamination between test and control regions, and flag any confounding events.

Causal Analysis

We apply the appropriate method — difference-in-differences, synthetic control, or Bayesian structural time-series — to isolate the true incremental effect of your advertising.

Model & Framework

We translate experiment results into an ongoing measurement framework — a calibrated model for budget decisions without running a new experiment every quarter.

Ideal Client

This service is for you if…

E-commerce brands spending $100K+ per month on advertising who need defensible ROI figures

DTC companies with boards or investors asking for rigorous ad effectiveness evidence

Retail businesses running brand advertising who need to measure long-term impact

CMOs who have been burned by platform attribution and want an independent, scientific answer

What clients see

True

Incremental impact

Unlike correlation-based models, causal inference tells you exactly what would have happened without your advertising — the true counterfactual.

40%

Non-incremental spend found

Many brands discover a significant proportion of attributed conversions would have happened anyway — without any ads.

Common questions

What's geo-holdout testing?

We pause advertising in a carefully selected set of markets while maintaining it in similar markets. The difference in outcomes between held-out and control markets reveals the true causal impact.

How is this different from platform lift studies?

Platform lift studies are run by the platform itself using their own methodology. Our causal inference work is platform-independent and typically more rigorous than platform-native lift products.

Do we have to pause advertising in some markets?

For geo-holdout experiments, yes — typically in markets representing 15–25% of volume. We design the holdout to minimise business risk while maximising statistical power.

Can we do this for brand campaigns?

Yes — and brand campaigns are often where causal methods are most valuable, because brand impact is typically not captured by last-click or multi-touch models.

Other services

Marketing Analytics Audit

A comprehensive review of your data stack, KPIs, and attribution gaps. We surface exactly where your measurement is broken and what it's costing you.

$3,000 – $8,000

Advertising ROI Modeling

Causal models that link ad spend directly to revenue and profit — not correlation, not last-click. Built for e-commerce, DTC, and retail teams who need to justify every dollar.

$5,000 – $15,000

Conversion Rate Optimization

Structured testing frameworks that eliminate guesswork. We design experiments with proper statistical power, monitor them correctly, and deliver conclusions you can act on with confidence.

$4,000 – $12,000

Currently accepting new clients

Ready to prove your marketing ROI?

Book a free 30-minute consultation. No commitment, just 30 minutes of clarity on what's actually driving your results.

Book Free Consultation

No commitment. Just 30 minutes of clarity.