E-commerce analytics · revenue · margin · funnel · retention

Connect sales, customers and marketing. See what makes e‑commerce profitable.

I build analytics that shows not only how much the store sold, but why the result changed, where customers drop out, which acquisition channels pay back and what drives repeat purchase.

GA4, Piwik PRO, GTM, BigQuery, Looker Studio, Power BI and advertising platforms are delivery tools. We first agree the decisions, store economics, systems of record and KPI definitions.

The order as the reference pointstatus, payment, refund, discount, cost and net revenue
The customer and pre-purchase funnelsource, device, product, basket, checkout and return
Performance after marketing costROAS in the context of margin, CAC, retention and attribution limits

Signals that tracking is not enough

The data is spread across systems, yet the store result is still hard to explain.

The usual problem is not the absence of another dashboard. It is the lack of an agreed sales definition, a known source for each number and a way to connect customer behaviour to the actual order result.

GA4 and the store report different sales

Duplicates, consent, script blocking, currencies, cancellations and refunds change the transaction picture.

ROAS looks good, margin does not

Campaign reports omit discounts, product cost, delivery, refunds and category-level profitability.

The funnel drops without a clear cause

It is unclear whether the issue is the device, product, traffic source, delivery or a specific checkout step.

Every purchase looks the same

New, returning and promotion-driven customers are merged into one result without cohorts or retention.

Campaigns lose their context

UTMs, click identifiers and campaign names are inconsistent, while owned channels distort acquisition source.

Reporting remains manual

Marketing, e-commerce and finance merge exports and recreate the same definitions in spreadsheets every week.

E-commerce analytics model

One path from source to decision, with a clearly named system of record.

I do not force every tool to show an identical result. I define source roles, reconciliation rules and tolerances so differences are understood and controlled.

01 · Sources

Store, payments, refunds, CRM, media and web analytics

Each system has its own refresh rhythm, identifiers and limitations.

02 · Model

Order, line item, customer, session, channel and calendar

Systems of record, keys, statuses, currencies, costs and KPI definitions.

03 · Views

Commercial result, funnel, channel, product and customer

Decision-level reporting with a path from a variance to its likely cause.

04 · Action

Budget, offer, checkout, retention and test priority

A decision owner, response threshold, next step and outcome check.

The store or ERP reconciles ordersweb analytics explains behaviour, not the sales ledger
Definitions come before the dashboardrevenue, customer and channel cannot change between reports
Reconcile first, optimise seconda decision should not be based on an implementation error

Six decision lenses

Reporting scope follows store economics and management practice.

Not every store needs every area on day one. We prioritise by expected business impact and the quality of available data.

  1. 01

    Commercial performance

    Orders, gross and net revenue, discounts, cancellations, refunds, average order value, product cost and margin.

    Decision: what truly creates the result
  2. 02

    Acquisition and profitability

    Campaign cost, CAC, ROAS, new-customer share, profitability after media cost and attribution limits.

    Decision: where to increase or reduce budget
  3. 03

    Funnel and checkout

    Product list, product page, basket, checkout start, payment, errors, device, source and delivery option.

    Decision: which stage needs diagnosis or testing
  4. 04

    Product and merchandising

    Visibility, interest, basket additions, conversion, discount, refund, availability and category profitability.

    Decision: what to promote, improve or retire
  5. 05

    Customer, retention and LTV

    New and returning customers, cohorts, time to next purchase, frequency, customer value and segments.

    Decision: whom to acquire and how to retain them
  6. 06

    Quality and governance

    Transaction completeness, identifier consistency, freshness, KPI owners, documentation and change process.

    Decision: whether the data is trustworthy

Example cockpit

The report starts with the outcome, then leads to cause and action.

This mock-up shows how information can be organised. It is an illustration, not client data or a promised implementation result.

Data reconciliation

Every number has a definition, a source and a point when it is safe to use.

GA4 does not need to match the store transaction by transaction. The difference, its scale and the source accountable for each decision must be clear.

AreaSystem of recordPurposeControls
Order and revenueStore or ERPcommercial outcome and fulfilment statusduplicates, currency, discounts, cancellations
Payment and refundPSP, store or ERPsettled revenue and adjustmentsstatus, date and partial refund
Behaviour and funnelGA4 or Piwik PROjourney, context and segmentationconsent, events, parameters and data loss
Campaign costAdvertising platformspend, clicks and deliverycurrency, time zone and campaign structure
Customer and retentionCRM, store or CDPcustomer status, cohorts and valueidentity, consent and change history

Engagement options

The work can start with measurement repair or a complete profitability model.

After a short qualification, I recommend the smallest useful scope. Not every problem requires a warehouse, server-side tracking or a tool migration.

01

Audit and remediation plan

Assessment of implementation, sources, discrepancies, definitions and reports.

  • problem and risk map
  • impact-based priorities
  • testing and delivery plan
Best when the data is not trusted
02

Behaviour and sales measurement

Measurement plan, dataLayer, GA4 or Piwik PRO, tags, consent and QA.

  • funnel and e-commerce events
  • identifiers and business parameters
  • documentation and acceptance
Best when the foundation is incomplete
03

Integration and trading cockpit

Store, campaign and behaviour data, optionally enriched with CRM or cost.

  • data model and KPI layer
  • dashboards and analysis
  • automation and monitoring
Best when full economics is needed
04

Ongoing support and development

Quality control, performance analysis, backlog and collaboration with marketing and IT.

  • recurring KPI review
  • diagnoses and recommendations
  • measurement that evolves with the store
Best when analytics must work continuously

Working process

Decisions and economics first, technology second.

  1. 01

    Decisions, KPIs and store model

    Audiences, operating rhythm, order, margin, customer and channel definitions, and required cuts.

    Outcome: decision brief and KPI dictionary
  2. 02

    Source inventory

    Store, payments, ERP, CRM, consent, web analytics, advertising platforms, identifiers and quality.

    Outcome: data and gap map
  3. 03

    Measurement and data-model design

    Events, dataLayer, keys, statuses, integrations, systems of record, architecture and test plan.

    Outcome: implementation specification
  4. 04

    Implementation and integration

    Agreed tool configuration, transformations, cost imports, dashboards and automation.

    Outcome: working data flow
  5. 05

    Validation and reconciliation

    Scenario tests, deduplication, order and value checks, refunds, consent, campaigns and tolerances.

    Outcome: acceptance record and known differences
  6. 06

    Operational adoption

    Training, owners, alerts, review agenda, analysis backlog and change-management rules.

    Outcome: analytics embedded in the team

Acceptance criteria

The implementation is ready when the team understands data quality and can use the result.

Specific thresholds are agreed before delivery. Platforms and consent create natural differences, so we accept both verified consistency and documented limitations.

A purchase does not duplicate after refreshtransaction identifiers and dispatch logic prevent repeated counting
Order value has one definitiontax, delivery, discount, currency, cancellation and refund are documented
The funnel passes scenario testsproducts, variants, basket, checkout, payment, errors and devices are checked
Campaign identity survives the journeyUTMs and click IDs are controlled through landing, payment and redirects
Every KPI has a source and ownereach result has a definition, frequency and responsible decision-maker
Known gaps are explicitconsent, ad blocking, cross-device, delays and attribution limits are documented

Honest limitations

Good measurement reduces uncertainty. It does not remove it.

  • GA4 and Piwik PRO do not replace transaction systems.Store, payment or ERP data is needed to reconcile sales, refunds and margin.
  • ROAS is not profitability.Campaign revenue must be set against margin, discount, product cost, refunds and acquisition cost.
  • Attribution is not proof of causality.A model organises channel contact but does not automatically measure incremental advertising impact.
  • Not every journey can be connected.Consent, ad blocking, cross-device use, authentication and platform limits fragment data.
  • Server-side and CAPI do not bypass privacy.They may improve control, but still require an appropriate basis, consent and configuration.
  • A dashboard does not make the decision.It needs an owner, response threshold, business context and an outcome check.
Krzysztof Surowiecki

Business, measurement and the data layer

I connect e-commerce, marketing, implementation and reporting perspectives.

I lead the work from management questions and order economics, through measurement design and integrations, to dashboard acceptance and team adoption. Technology remains a means, not the goal.

20+years of experience
150+analytics and data projects
50+clients

Figures refer to the broader analytics and data practice, not only e-commerce implementations.

Before we talk

Frequently asked questions.

Why does GA4 revenue differ from the store?

GA4 measures browser or app behaviour and depends on consent, script blocking, purchase-event correctness and deduplication. The store knows order status, later cancellations and refunds. The store or ERP normally reconciles performance, while GA4 explains the journey and marketing context.

GA4 or Piwik PRO for e-commerce?

The choice depends on privacy, hosting, advertising integrations, reporting and the organisation's way of working. I do not recommend migration simply because one tool is more popular. Requirements and switching cost come first.

Do we need server-side tagging or Meta CAPI?

Not always. They can improve data-flow control, integration stability and event delivery, but introduce implementation and maintenance cost and do not remove privacy obligations.

Can the store, campaigns and CRM be connected?

Yes, when sources expose stable identifiers and suitable detail. The work needs matching rules, a customer model, access controls and documentation of journeys that cannot be linked.

Can the report include margin and LTV?

Yes, but GA4 alone does not know product cost, refunds or full customer history. Margin and LTV require store, ERP or CRM data and agreed definitions, horizons and cost-allocation rules.

Can we start with an audit only?

Yes. It is often the right first step for a complex implementation or material discrepancies. The audit ends with an impact assessment, priorities and remediation plan without committing to a full implementation.

First step

Start with three decisions and the sources that currently give different answers.

Describe your commerce platform, current measurement, payment system, marketing channels and the reports the team does not trust or still lacks.

Calculate and organise

Useful tools before the project.