Why Google Tag Manager is not recommended for use with AI Commerce Cloud
Discover the limitations of using Google Tag Manager with AI Commerce Cloud and the alternative solutions available for optimizing data management.
Written by Petro Mäntylä
Updated at May 12th, 2025
Table of Contents
AI Commerce Cloud already includes a Google tag (gtag.js) for GA4 measurement and Google Ads conversion tracking, and also sends events via the server-side Measurement Protocol; therefore, adding a separate Google Tag Manager (GTM) container does not add value, but can double conversions, skew reports, and degrade page performance.
Terms & technology
| Element | Purpose | Where to use | Supports third parties? |
|---|---|---|---|
| Google tag (gtag.js / “Google Tag”) | A single script that sends data to GA4, Google Ads, CM360, etc. | Direct <script> on the page or inside a GTM container | No |
| GA4 configuration tag | Launches the GA4 property and links cookies and settings. | Direct code or GTM | No |
| Google Ads conversion tag | Event-specific snippet that reports campaign conversion (requires Google tag or GTM). | Triggered at the moment of purchase/lead | No |
| Google Tag Manager (GTM) | Tag management system: a single container can load Google and third-party tags without any code changes. | One container snippet per page | Yes |
What AI Commerce Cloud already does
- gtag.js is automatically added to every page and passes page_view and e-commerce events to the GA4 property.
- Google Ads conversions are sent using both the browser's gtag.js code and the server-side Measurement Protocol; transaction_id deduplicates any duplicates.
- Consent Mode v2 is integrated without a GTM script.
Risk: duplicate & erroneous data with GTM
- Two-level implementation: The GTM container often includes its own Google tag, causing the same page_view or purchase to be triggered twice and recorded as a double conversion.
- Incorrect attribution in Google Ads: double reporting distorts ROAS and CPA figures.
- Performance: additional scripts increase load time and slow down the Largest Contentful Paint metric.
- Cookie consent management becomes more complicated because multiple layers of tags require separate consent connections in the CMP.
When is GTM still useful?
| Need | Is GTM justified? | Argument |
|---|---|---|
| Third-party pixels (TikTok, LinkedIn, Hotjar…) | Yes | GTM allows these to be published without code changes. |
| A/B testing tools or marketing scripts not natively supported by AI Commerce | Yes | The container serves as an easy publishing channel. |
| Just GA4 + Ads (already built-in) | No | No additional benefit, risk of double conversions and slowdown. |
Summary
“ AI Commerce Cloud already has Google tag and Google Ads conversions built in, both on the browser and server side. Tag Manager doesn’t bring additional data to GA4 or Ads, but it can trigger the same events twice and skew your reports. You should only implement GTM if you want to add third-party pixels that the platform doesn’t natively offer. Otherwise, we recommend sticking with the current solution.”