Google Consent Mode v2: Why Your Remarketing Audiences Are Empty (and How to Fix It)

Since March 2024, a wave of panic has silently swept across the Google Ads accounts of Swiss companies. CPA (Cost per Acquisition) is rising, and remarketing audience lists are drying up.

The reason is not poor campaign management by your agency. The reason is technical: the absence of Google Consent Mode v2.

At A-Track, we find that 60% of websites in French-speaking Switzerland have not yet made this mandatory update. The result? Google considers them non-compliant and throttles their data.

Here is the definitive guide to understanding, implementing, and saving your advertising performance with Consent Mode v2, while respecting the nFADP.

What is Google Consent Mode v2? (Definition)

Consent Mode is not a "cookie banner". It is a communication mechanism between your banner (CMP) and Google tags (Analytics, Ads, Floodlight).

It adds two new signals (parameters) sent to Google:

1. ad_user_data: Does the user agree to have their data sent to Google for advertising purposes?

2. ad_personalization: Does the user agree to remarketing (personalized advertising)?

Without these explicit signals set to "GRANTED", Google assumes by default that it is a refusal.

The Concrete Impact for Agencies and Advertisers

If you do not activate it, here is what happens technically on your accounts:

• Stop of Remarketing: You can no longer target visitors to your site (or "abandoned carts") on Google Ads, YouTube, and Gmail.

• Degraded Conversion Tracking: Google loses track of conversions after clicks, making Smart Bidding (automated bidding) blind.

• Loss of Revenue: Less data = less effective algorithms = ROAS in free fall.

Basic vs Advanced: Which Strategy to Choose for Switzerland?

There are two ways to implement Consent Mode. The choice depends on your risk appetite and your interpretation of the nFADP/GDPR.

1. The "Basic" Mode (Maximum Legal Security)

This is the strict mode.

• Operation: Google tags are completely blocked until the user clicks "Accept".

• Advantage: 100% compliant with GDPR and nFADP.

• Disadvantage: You lose 100% of the data from users who refuse or ignore the banner.

2. The "Advanced" Mode (Maximum Performance - Recommended by A-Track)

This is the hybrid mode that saves your statistics.

• Operation: Google tags load before consent, but send anonymized data (pings without cookies).

• The Magic (Modeling): Thanks to these "pings", Google uses AI to model the missing conversions. You recover about 70% of the lost conversions in your reports.

• Compliance: Google ensures that no personal data is stored without consent. This is an acceptable compromise for most Swiss companies seeking performance.

Tutorial: How to Implement It with Google Tag Manager and Cookie-Script?

Do not ask your developer to code this "hard-coded". It is too complex to maintain. Use GTM.

Step 1: Choose a CMP Certified Google Partner Google requires the use of a certified CMP. At A-Track, we recommend Cookie-Script for its native integration and controlled cost for Swiss SMEs.

Step 2: Activation in GTM

1. In GTM, activate "Consent Overview" in the container settings.

2. Use the Template for tag "Cookie-Script CMP".

3. Check the box "Enable Google Consent Mode v2".

4. Set the default parameters (usually denied for all regions, or granted by default if you choose a nFADP flexible approach outside the EU, although risky).

Step 3: Updating Tags You do not need to modify each Google Ads tag. They automatically detect Consent Mode. However, for third-party tags (Facebook CAPI, LinkedIn), additional configurations via the DataLayer are necessary to respect user choice.

A-Track Expert Advice

Beware of false positives. We often see configurations where Consent Mode is 'enabled' in the plugin, but tags continue to trigger illegally before consent. Use Google's 'Tag Assistant' or the developer console (Network Tab) to check for the presence of the gcs and gcd parameters.