Google Tag Manager & Conversion Tracking
Your ad platforms are optimising ondata you cannot trust.
Broken tracking is the most expensive problem in digital marketing and the least likely to get fixed, because it is invisible until somebody goes looking. Seven years of building, auditing and repairing measurement setups — GTM, GA4, server-side and consent.
Container audit — findings
previewThe symptoms are always the same four.
If any of these sound familiar, the tracking is the problem and everything downstream is inheriting it.
GA4 and the ad platforms disagree
Google Ads says 84 conversions, GA4 says 61, Meta claims 130, and the CRM has 40 actual enquiries. Everyone reports their own number and nobody reconciles them, so every meeting starts with an argument about whose figure is right.
Conversions fire twice, or not at all
A thank-you page that gets refreshed. A tag on a click instead of a submission. A form that redirects before the tag fires. All of it silently corrupting the signal your smart bidding is learning from.
Nobody knows what is in the container
Forty tags, no naming convention, several from an agency you left in 2022, at least two doing the same job. Nobody wants to delete anything in case it breaks something nobody can name.
Consent broke it and nobody noticed
A cookie banner went in, Consent Mode was never configured properly, and either tags fire before consent (a legal problem) or a third of your data quietly vanished (a measurement problem). Often both.
How I fix measurement.
A dataLayer designed on purpose
Most containers are a pile of Click Classes and Page Path triggers held together by luck. They break every time a developer renames a CSS class. The fix is a specified dataLayer: a documented contract between your site and your measurement, so tracking survives a redesign.
- Written dataLayer specification your developers can implement against
- Trigger logic based on events, not fragile CSS selectors
- Naming conventions and folder structure so the container is navigable
- Version notes and a change log so you can see who changed what, and when
Container after cleanup
previewServer-side and Consent Mode v2, properly
Browser tracking keeps getting less reliable and consent requirements keep getting stricter. I have built GDPR-compliant setups where no cookies fire before consent, and full-stack GA4 with consent management for a global business. The point is to stay legal without throwing away a third of your data.
- Consent Mode v2 configured against your CMP, tested state by state
- No tags firing before consent, verified rather than assumed
- Server-side GTM where it earns its hosting cost
- Enhanced conversions and Meta Conversions API with correct deduplication
Consent state testing
previewDistinct actions tracked
30+
Single site, feeding Power BI
Numbers that reconcile with the back office
The end state is not a tidy container, it is a set of numbers you can put in front of a board. That means agreeing an acceptable variance between GA4, the ad platforms and your actual sales system, then getting inside it and documenting why the gap exists.
- Purchase deduplication, refund handling and revenue accuracy checks
- Conversion imports into Google Ads and Meta from your CRM
- Reporting layer in Looker Studio or Power BI, including DAX where needed
- A written QA and handover pack so the next person is not guessing
Reconciliation, after the fix
Consent-compliant setups
GDPR
No cookies before consent
Everything that is on the table.
Most people start with the audit. It is the only way to know which of these you actually need.
- Full GTM container audit with written findings
- Container cleanup, naming conventions and governance
- dataLayer specification and developer documentation
- GA4 property setup, migration and event modelling
- GA4 e-commerce and items array implementation
- Server-side GTM setup and hosting guidance
- Consent Mode v2 and CMP integration
- GDPR and Australian Privacy Act compliant configurations
- Enhanced conversions for Google Ads
- Meta Conversions API with event deduplication
- Offline and CRM conversion imports
- Call tracking and form tracking implementation
- Cross-domain and subdomain tracking
- Custom JavaScript variables and tags
- Debugging, QA methodology and test documentation
- Looker Studio and Power BI reporting layers
This is also the service I most often deliver white-label for agencies who want the tracking right without hiring for it. Happy to sign a non-solicitation agreement.
Measurement work, at scale.
Seven years of analytics builds across agency, in-house and global businesses.
30+
Distinct user actions tracked through Google Tag Manager on a single 2,000-page site, feeding a full Power BI reporting stack
GDPR
Compliant technical implementations with no cookies set before consent, across multiple multinational clients
7 yrs
Building, auditing and repairing GA4 and Universal Analytics setups agency side and in-house
Board
Level reporting on ROI, CAC and CPA at a global affiliate network, built on tracking I implemented and maintained
Client names withheld under agency and contract terms. Happy to talk specifics on a call.
How a tracking project runs.
Audit first. Nobody should rebuild a container they have not read.
Audit
One to two weeks, fixed price. Container, GA4 property, ad platform conversions and consent setup, tested against real user journeys, written up with severity and business impact.
Measurement plan
A short document agreeing what should be tracked, what each event means, what it is worth and who needs to see it. Signed off before anyone builds anything.
Build and QA
Implementation in GTM, GA4 and the ad platforms, tested in every consent state and on real devices, with the QA evidence written down rather than asserted.
Handover
Documentation, a change log, and a walkthrough with whoever inherits it. Optionally a training session so your team can maintain it without calling me.
Whether a tracking audit is worth paying for.
It is the highest-leverage thing I do, but not for everyone.
This is a good fit if
- You are spending money on paid media and the platform numbers do not match reality
- You are running smart bidding, which is entirely dependent on the conversion signal
- You have replatformed, redesigned or added a cookie banner in the last two years
- You inherited a container from a previous agency and nobody has read it since
- You are an agency who wants this done properly without hiring a specialist
Call someone else if
- You have almost no traffic yet — get some first, the audit will keep
- You have a simple brochure site with one contact form and no paid media
- You want somebody to tell you the setup is fine without actually checking
- You need the numbers to say something specific for a report that is already written
- You are not willing to change anything based on what the audit finds
Trackingquestions.
Something not covered? Ask me directly — you will get a straight answer, not a proposal.
How long does an audit take?
One to two weeks depending on how much is in the container and how many platforms are connected. You get a written document with findings ranked by business impact, not a spreadsheet of every minor warning.
Can you work with our existing container?
Almost always, and I prefer to. Wholesale rebuilds break historical data continuity and are usually unnecessary. I clean up, restructure and document what is there, then rebuild only the parts that genuinely cannot be saved.
Do we need server-side tracking?
Probably less often than you have been told. It genuinely helps high-volume e-commerce, businesses with strict consent requirements, and anyone badly hit by browser restrictions. For a lot of businesses it adds hosting cost and complexity for marginal gain. I will tell you which you are.
Will fixing the tracking improve our ad performance?
Often yes, and sometimes substantially, because smart bidding is only as good as the signal it learns from. But I will not promise a number. What I will promise is that afterwards you can tell whether it is working, which you currently cannot.
Do you work white-label for agencies?
Yes, regularly. I work under your brand, in your client accounts, and I do not approach your clients — I will sign a non-solicitation agreement confirming that. There is also a training programme if you would rather build the capability in-house.
What do we get at the end?
A working setup, a written measurement plan, QA evidence for each event in each consent state, a container change log, and a walkthrough session. Everything in your own accounts, under your ownership.