E-commerce analytics & conversion measurement in PrestaShop
First we check whether GA4, GTM and your PrestaShop data capture purchases and the key funnel stages according to an agreed measurement plan. We fix confirmed errors, document the setup and show the limits of the data. We don't promise a conversion uplift before analysis — reliable measurement helps identify problems and formulate hypotheses for later verification.
The problem
A gap between GA4 and PrestaShop orders rarely has a single cause. Depending on the store, it may stem from the timing of the purchase event, the return from a payment gateway, duplicated transactions, a wrong transaction_id, consent configuration, blocked scripts, or simply GA4 and the shop counting sales by different definitions. This isn't solved by adding another module or rolling out server-side tracking blindly — first we separate the data-completeness problem from the attribution problem and from plain reporting differences. We usually look at several layers at once:
- The purchase event doesn't fire for some payment methods or after returning from an external gateway
- The same order reaches GA4 more than once — duplicated transactions inflate the numbers
- A purchase is measured before payment is confirmed, or skipped after the order status changes
- The payment provider shows up in GA4 as a referral and takes over the original traffic attribution
- Product identifiers differ between the store, the feed, GA4 and Google Ads
- The consent mechanism fires tags in the wrong order or with an incorrect default state
- GA4 and the shop compare different order statuses, time zones, currencies or revenue definitions
- Refunds and cancellations aren't reflected in the data, so the reported result is overstated
When you should consider this
- GA4 misses or duplicates some orders compared with the PrestaShop admin
- Different payment methods produce different results when measuring purchases
- Google Ads, GA4 and PrestaShop show three different numbers for the same sales
- Data quality dropped noticeably after changing a module, the checkout or the consent banner
- It's unclear which checkout stages are actually being measured
- The GTM container has no documentation and no safe publishing process
- You want server-side tracking, but first want to check whether scale and the problem justify it
- Marketing needs margin or profitability data that standard GA4 doesn't calculate out of the box
- You need a stable baseline before running CRO tests
Scope of work
Plan and audit
- Measurement plan — definitions of macro- and micro-conversions, events, parameters, data sources and counting rules, matched to the store's purchase funnel
- GA4, GTM and dataLayer audit — properties, streams, tags, triggers, variables, identifiers, environments and container versioning
Purchase path and the purchase event
- PrestaShop purchase path — product lists, product page, cart, checkout, shipping and payment methods, purchase and returns
- Purchase event and order lifecycle — where and when it fires, payment status, confirmation-page refreshes, deduplication and differences between payment modules
Consent, reconciliation and advanced solutions
- Consent and advertising products — technical integration with the CMP, Consent Mode v2, Google Ads and Enhanced Conversions per the client's approved rules
- Reconciliation with store data — comparing purchase events with orders for an agreed period, statuses, currencies, time zone, cancellations and refunds
- Advanced solutions, only where justified — Measurement Protocol, server-side GTM, BigQuery export, Looker Studio dashboards, margin data and data-quality monitoring
What you get
Diagnosis and data
- A measurement plan matched to your store's purchase funnel
- A report of confirmed problems, their impact and priority — backed by evidence from tests
- A comparison of GA4 purchase events against an agreed set of PrestaShop orders
Implementation and verification
- Implemented and versioned changes in GTM, code or the tracking module, when implementation is part of the engagement
- A matrix of tested payment methods, devices and consent variants
- Before/after verification results
Documentation and next steps
- Documentation of events, dataLayer parameters and dependencies
- A list of known limitations, risks and recommended next steps
What the report gives you for each issue
What we check
- The tested scenario and expected behavior
- The actual state and evidence from testing (GTM Preview, DebugView, network requests, logs)
- Impact on data completeness, attribution or business decisions
What we establish
- The confirmed cause, or a note on what hasn't been confirmed yet
- Recommended solution
- Priority, dependencies and implementation estimate
What happens next
- How it's verified after implementation
- The test result, or the reason for leaving a limitation in place
How the process works
Definitions and scenarios
We agree what counts as a purchase, which order statuses we compare and which customer paths matter most for the business, then pick representative scenarios to test.
Baseline measurement
We test devices, payment methods, consent states and a sample of orders, and record the current discrepancies between GA4 and actual orders.
Diagnosis
We separate event loss, duplication, attribution problems, reporting differences and consent-related limits — pointing to confirmed causes, not guesses.
Change plan
You get recommendations with priority, implementation effort, risk, dependencies and the expected, measurable effect on data quality. Together we decide what to implement.
Implementation and testing
We implement on a staging environment where possible and verify in GTM Preview, DebugView, network requests, logs and order records.
Post-launch verification
We compare results against the baseline over an agreed period and document the remaining differences and what's worth monitoring further.
- 1
Definitions and scenarios
We agree what counts as a purchase, which order statuses we compare and which customer paths matter most for the business, then pick representative scenarios to test.
- 2
Baseline measurement
We test devices, payment methods, consent states and a sample of orders, and record the current discrepancies between GA4 and actual orders.
- 3
Diagnosis
We separate event loss, duplication, attribution problems, reporting differences and consent-related limits — pointing to confirmed causes, not guesses.
- 4
Change plan
You get recommendations with priority, implementation effort, risk, dependencies and the expected, measurable effect on data quality. Together we decide what to implement.
- 5
Implementation and testing
We implement on a staging environment where possible and verify in GTM Preview, DebugView, network requests, logs and order records.
- 6
Post-launch verification
We compare results against the baseline over an agreed period and document the remaining differences and what's worth monitoring further.
Why this works
Most measurement problems in PrestaShop sit at the seam between layers — the payment module, the store code, the dataLayer, GTM and the server. We work across that whole range: PrestaShop and PHP, the database, Linux and DevOps, plus GA4, GTM and integrations. That means we don't bounce you between a "developer" and an "ads specialist" — one accountable person follows the thread from the browser, through when the event is sent, all the way to the order status and events sent from the backend. Our aim is data you can trust, not impressive-looking numbers in a proposal.
Conditions for a reliable result
Before we start, we agree on the reference data: order statuses, reporting period, time zone, currencies, refunds and test orders. A full audit may require access to GA4, GTM, the CMP, store code, module configuration and order data. We don't guarantee a perfect match between GA4 and the store database, or a conversion uplift from tracking alone — some data stays unavailable because of user decisions, technical blocking or platform limits, and modeled data is an estimate, not a recovery of observed events. We implement server-side tracking only when its benefit justifies the extra infrastructure and maintenance. We configure how consent signals are passed technically, per the approved CMP setup; we don't decide the legal basis, banner wording or retention rules for the client, and the technical implementation itself is not a legal-compliance assessment.
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