Marc Alexander, Google Analytics (GA4) consultant
Brought in when the numbers stop adding up. Marc is a senior GA4 consultant and Google Analytics expert who finds the fault, fixes it at source and hands over a build your in-house team can run. He has 10 years in digital analytics, most recently at Halfords, and before that led web analytics across Knight Frank's 50+ international websites.
Results from recent work.
- Over 18%of more than 12 million checkout page views at Halfords were overstated. Each fault was traced to its cause and the fixes specified
- 27%more qualified leads at Knight Frank, after finding an 80% drop-off on high-value enquiry forms
- 70%fewer ad hoc reporting requests at Knight Frank, with dashboards linking digital performance to revenue and pipeline
- Under 2 weeksto get The Super Prime's full ecommerce funnel live in GA4, with zero back-end changes
The detail is in the case studies for Halfords, Knight Frank and The Super Prime.
Sound familiar?
Marketing and finance quote different revenue.
GA4 doesn't match Shopify, Stripe or the finance system, so every meeting starts with an argument about whose number is right. Usually missing item data, tax inside revenue or tracking lost at the payment step. Why GA4 revenue doesn't match.
Conversion rates look too good.
The same action fires two events, often because GA4 and a separate tag both track it, or a trigger fires twice. Fixing duplicate key events.
Direct is your biggest channel while campaigns are running.
Sessions break at a checkout domain or payment page, or campaign tags get lost, so paid traffic shows up as Direct. Why GA4 shows everything as Direct.
Nobody is sure the cookie banner works.
Tags fire before anyone clicks, or nothing is recorded whatever the visitor chooses. One is a compliance problem, the other a data problem. How to test Consent Mode v2.
Leads are counted, but nobody knows which became customers.
Form fills land in GA4 and the CRM separately, so marketing is judged on volume, not revenue. Joining GA4 to the CRM.
Nobody knows how the tracking was built.
An agency or developer set it up and moved on. It mostly works, but nobody on your side can say why, or check the numbers. When an agency runs your tracking.
What a GA4 consultant does.
Whether you call it a GA4 consultant, a GA4 expert or a GA4 specialist, the job is to make GA4 record what really happens on your site, and to make that data something the business can act on. In practice, that means you end up with:
- Key events counted once, so conversion rates are real
- Revenue that matches Shopify, Stripe or your payment processor
- Campaigns credited across checkout domains, instead of lost to Direct
- Consent Mode v2 that follows each visitor's choice under UK GDPR
- Leads followed into the CRM, so marketing is judged on customers, not form fills
- BigQuery and dashboards when the GA4 interface isn't enough
How the data flows when it's set up properly.
- Your websitePage views, clicks, purchases and forms, written to a dataLayer the site owns.
- ConsentConsent Mode v2 by region: nothing personal leaves until the visitor agrees.
- Google Tag ManagerOne container, every tag documented and checked against consent.
- Server-side taggingWhere it earns its place: one stream to your own subdomain, with control over what each platform gets.
- GA4 and ad platformsGoogle Analytics 4, Google Ads and Meta each get what they're allowed, once.
- BigQuery and reportingRaw data joined to the CRM and finance, and dashboards that match the ledger.
Do you need a GA4 consultant?
Probably, if…
GA4 drives decisions about budget or stock, you spend on advertising, you sell online or hand leads to a sales team, the site is changing platform, or nobody in-house has time to own the tracking.
Probably not yet, if…
You run a small site with one contact form and no advertising, and you mainly want to see visits. The free tracking checker, measurement plan template and guides will get you a long way.
Not sure?
The mini audit answers it, from £175. If nothing is wrong, the report says so and lists what was checked.
Ways to work together, and what they cost.
GA4 mini audit.
The usual first step: the areas that most often break, checked and ranked in a written report within 3 to 5 working days, from £175. See a sample report.
Full audit, or audit and fix.
All 38 checkpoints with a prioritised action plan, from £600, or with the high-priority problems fixed and tested, from £1,000. About the 38-point audit.
GA4 setup or rebuild.
A basic setup is typically £350 to £600, and an advanced one, with custom events, detailed ecommerce and cross-domain tracking, £850 to £1,300. About GA4 setup.
Monthly support.
Monitoring, changes as the site evolves and someone to call, typically £500 to £2,000 a month. About monitoring.
Contract analytics lead.
Someone to own your analytics for a fixed period, as at Halfords for six months, from the day rate of £800 to £1,200 a day. About contract work.
GA4 contractor.
Hands-on GA4 and GTM work for three months or more, through Marc's limited company and outside IR35, typically £400 to £500 a day. About contracting.
Every price is on the pricing page, and the cost estimator adds them up for your project. You get a fixed quote before anything starts.
How a project runs.
Audit
What's working, what isn't and what it costs the business, ranked in a written report within 3 to 5 working days.
Plan
The questions the business needs answered, and the events and key events that answer them, agreed in a measurement plan. Specific reports, not "track everything".
Build and test
GA4 and Tag Manager fixed or rebuilt, tested across devices with consent granted and refused, and checked against real orders or leads.
Hand over
Documentation, a walkthrough and training for your team, with monthly support if you want someone to call when the site changes.
What you keep at the end.
- A GA4 property configured and checked against the list below
- A measurement plan: the questions, the key events that answer them and who owns each
- A dataLayer specification your developers can build against
- A documented Tag Manager container, with version notes on every change
- A record of what was tested, including consent granted and refused
- Training and a walkthrough, so your team can make common changes safely
Checked in every GA4 property.
- Data retention set to 14 months, not the default 2, so explorations can look back over a year
- Internal and developer traffic filtered out
- Payment providers listed as unwanted referrals, so they don't take the credit for sales
- Purchases sent with a transaction ID, so a refreshed confirmation page doesn't count the order twice
- Revenue sent without tax and shipping, with the currency on every ecommerce event
- Cross-domain tracking where the journey crosses domains
- Consent Mode defaults set before any tag fires, and tested with consent granted and refused
- Google Ads linked, with the right key events imported as conversions
- Custom dimensions registered for the parameters reports depend on
- The BigQuery export switched on early, as it only keeps data from the day it starts
New to some of these terms? The GA4 glossary explains them in plain English.
Problems solved recently.
Direct traffic that was really bots.
For a direct-to-consumer Shopify retailer, a large share of reported Direct traffic turned out to be automated. The clusters behind it were isolated, and a traffic quality layer now sends analytics events only for verified human sessions, giving the client a trustworthy baseline for the first time.
Product data silently dropped.
For a health technology platform, a fault had been dropping product data out of ecommerce events without any error. Tracing and fixing it restored revenue and product reporting.
Customer matching failing without errors.
At Halfords, customer records weren't matching between the storefront, the customer data platform and the ad platforms. The fault was traced to its source, with a written data standard that no supplier had owned.
A decline blamed on the wrong cause.
Also at Halfords, a drop in conversions was blamed on switching off an experimentation tool. The data showed it began before the switch-off, amid three other events that week, so a permanent decision on that evidence was advised against.
Questions to ask any GA4 consultant.
Whoever you hire, these questions separate careful work from guesswork. Here's how Marc answers them.
Who will do the work?
Marc, from the first audit to the handover. No account manager, and no junior learning on your account.
Will we get a fixed price?
Yes. A fixed quote once the scope is agreed, and nothing starts until you've accepted it. Any change is priced and agreed in writing first.
How will you prove it works?
Every change is tested with consent granted and refused, across devices, and checked against real orders or leads, not just GA4's own reports.
Do you also sell advertising?
No. There's no media buying, so there's no interest in making the numbers look better than they are.
Whose accounts will it live in?
It should be yours, documented well enough to hand to someone else. Ask before any work starts. Choosing a consultant or an agency covers what else to check.
Background.
A Google Analytics 4 specialist who has done the work in-house and as a consultant, and now runs Metric Owl, an independent Google Analytics consultancy.
- Lead analytics consultant at Halfords for six months in 2026, leading 14 workstreams. The Halfords case study
- Senior Web Analytics Specialist at Knight Frank from 2021 to 2025, leading web analytics across more than 50 international websites and delivering the move to GA4. Part of the team named Knight Frank's Project Team of the Year 2024
- Earlier in-house roles at WorldFirst, connecting Google Analytics to back-office systems for LTV, ROAS and cohort analysis, and VisitBritain, running all digital tagging through Google Tag Manager
- More than 60 GA4 implementations
- Google Analytics Certification (2025), Server-side Tagging with Stape (2026) and Contentsquare Certified Expert (2022)
More on the About page.
Case studies.
Straight answers.
What does a GA4 consultant do?
Makes sure Google Analytics 4 records what really happens on your site, in a form the business can use: auditing the setup, planning key events, building tracking in Google Tag Manager, making consent work and training the team. Marc does all of it himself.
How much does a GA4 consultant cost?
The usual first step is the GA4 mini audit, from £175. The 38-point audit is from £600, and a basic GA4 setup typically £350 to £600. Larger projects are quoted once the scope is clear. Try the cost estimator, or read what a GA4 consultant costs.
What's the difference between a GA4 audit and a GA4 setup?
An audit checks an existing setup and says what's wrong, in what order to fix it and how. A setup builds the tracking: the property, the events, Tag Manager, consent and the Google Ads link. If you already have GA4, an audit usually comes first, because it shows whether a fix is enough or a rebuild is needed.
Should we hire a GA4 specialist or train someone in-house?
Both can work. A specialist is quicker when the setup is broken, a deadline is close or the site is changing platform. Training pays off once the setup is right, which is why every project ends with documentation and training for your team.
How long does a GA4 project take?
The mini audit takes 3 to 5 working days and the 38-point audit 7 to 10 working days. A basic GA4 setup takes 2 to 3 weeks. An advanced one, with custom events, detailed ecommerce and cross-domain tracking, takes 4 to 6 weeks.
How do I know if my analytics is broken?
Common signs: revenue or lead numbers that don't match other systems, conversion rates that look too high or too low, Direct traffic dominating while campaigns are running, or events nobody remembers setting up. The mini audit answers it one way or the other.
Do I need Consent Mode v2?
If you collect data from UK or EU visitors, yes. It lets GA4 and Google Ads respect each visitor's consent choice, and Google requires it for ads personalisation and remarketing in the EU. It is part of every GA4 setup, tested to confirm it changes what is collected.
Do you work with Shopify, WooCommerce and Magento?
Yes, as well as BigCommerce, Salesforce Commerce Cloud and custom platforms. Shopify's checkout no longer runs Tag Manager, so it's tracked with Customer Events, and WooCommerce and Magento need careful Tag Manager work. There is a dedicated Shopify setup.
Do you need access to our accounts?
For the mini audit, viewer access to the GA4 property and read access to the Google Tag Manager container are enough. Nothing is changed. Building or fixing needs edit access, agreed before work starts.
Do you work with GA4 360?
Yes. Halfords runs GA4 360 on a large Salesforce Commerce Cloud site. The work there included a cost model comparing server-side tagging with GA4 360 hit costs.
Will you train our team?
Yes. A basic GA4 setup includes an hour of training and an advanced setup two to three hours, and every project ends with documentation and a walkthrough. Longer training is quoted from the day rate.
Can you work alongside our agency?
Yes. At Halfords, the server-side build was handed to the agency with a nine-step cutover and 25 staged tests. Agencies also bring Marc in for the GA4 or Tag Manager part of a client project.
Do you work with clients outside the UK?
Yes, mostly remotely. There are pages for US, European, Canadian and Australian and New Zealand businesses, with prices in local currency.
Further reading: the 10 GA4 checks that stop broken data, how to build a measurement plan, key events vs conversions, how to track AI traffic and why the GA4 interface isn't a reporting tool.
Not sure how big the problem is? Start with the mini audit.
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What does your site fire before consent?
Paste a page address. The tracking checker shows what a first-time visitor triggers before agreeing to anything, ranked by how much it matters.
“It's been a real pleasure working with Marc. He's a talented and highly competent professional whose contributions across product development and analytics have been invaluable. I've appreciated his collaborative spirit and sharp insight. I would gladly recommend him to any team.”
Talk to Marc about it.
Tell Marc what's happening with your tracking. The quickest place to start is usually a GA4 mini audit: a prioritised list of what's broken and what to fix first.
Mini audit from £175.
Prefer to talk first? Choose "20-minute intro call" in the form.
Or email [email protected].