The client's starting goal
Shopify store selling professional haircare products in Belgium, France and the Netherlands, with GTM and advanced Consent Mode driven by the consent banner. In late August, purchases seen by Google Ads dropped from 42 to 3 a day, while GA4 kept counting 65 to 90: campaigns were losing their signal and no one knew why.
Key actions
We ruled out the possible causes one by one (GTM, Google Ads account, mobile) until we found the real one: the banner configuration had been republished empty, and every new visitor stayed in denied consent. At the same time, product IDs in the Shopping feed no longer matched those in the tags.
- Evidence-based diagnosis: consent state read in the page, GTM version unchanged, causes ruled out one by one
- Fix requested from the banner vendor, then consent testing after republishing
- Feed rule fixed so the product ID is the same in Merchant Center and in the tags
- Purchase tags wired with the Merchant Center ID, feed country and language, ready to publish
The impact
After republishing, testing passed: granted consent recorded, Google Ads and GA4 signals “granted”, pings compliant. In the Merchant Center feed, 2,248 out of 2,248 products now carry the expected ID.
The recovery of purchase volume in Google Ads is still being measured.
