Data
McDonald’s Switzerland: +127% opt-in rate with OneTrust CMP optimization & A/B testing
McDonald’s Switzerland engaged Eminence to optimize their web consent rate through OneTrust CMP, including technical development, A/B testing and continuous improvement over 6 months.
Issue
Our mission was to optimize McDonald's Switzerland's web consent rate on the OneTrust CMP platform, improving first-party data collection and user experience. We faced the following challenges:
Consent optimization strategy:
- Prevent traffic loss and maximize opt-in
- Critical opt-in rate of only 15%
- 60% of users not providing any choice
- Technical issues on YouTube and SmartWebView
- Migration to OneTrust with GDPR/LPD constraints
Discover our achievements in web consent optimization, technical development and A/B testing strategy for an optimal user experience and maximized first-party data collection.
Technical Development
We developed YouTube Consent and SmartWebView solutions to solve critical consent issues and improve user experience across all digital touchpoints.
A/B Testing Program
Implementation of a 5-month continuous optimization program with monthly tests to identify the optimal consent banner configuration.
Multilingual CRO Strategy
We implemented a consent rate optimization strategy in 3 languages (FR/DE/IT), based on UX optimization, copywriting and visual hierarchy.
GDPR/LPD Compliance
Strict maintenance of GDPR and Swiss LPD compliance throughout the project, with legal validation of each test iteration.
Nos Outils
Google Analytics 4
Adobe Experience Manager
OneTrust
YouTube Consent Fix - May
- To solve the YouTube video consent issue, we:
- Developed two A/B tested creatives
- Implemented contextual consent system at user intent point
- Variant B "We share good moments... and cookies!" won
- Result: 20.8% opt-in rate (+5pt vs baseline 15%)
- Emotional approach validated as foundation for next step
SmartWebView Fix - June
Technical fix of consent banner on SmartWebView page:
- Display and navigation optimization
- Visual hierarchy improvement
- Result: 23.6% opt-in (+3pt vs YT Consent)
- Significant "Not Given Choice" rate reduction: 55.6% (-6.2pt)
A/B Testing Program - July to November
5-month continuous optimization program with monthly tests:
- Test 1 (July) - Initial Optimization: Centered overlay, engaging headline, clear value proposition → 32.7% opt-in (+9.1pt)
- Test 2 (August) - Visual Refinement: White reject button with yellow border → 31.2% opt-in (-1.5pt, slight regression)
- Test 3 (September) - Button Layout: Left-to-right order (reject-settings-accept) → 29.1% opt-in (-0.9pt, rollback needed)
- Test 4 (October) - Banner Size Increase: 60% page coverage + McDonald's logo → 33.5% opt-in (+6.4pt, strong recovery)
- Test 5 (November) - Primary CTA Optimization: Full-width accept button on top, optimized hierarchy → 34% opt-in (+0.5pt, BEST RESULT)
Key Learnings
What Works Best:
- Centered overlay with moderate size (800x500px) optimal
- Full-width yellow primary CTA significantly outperforms
- White reject button with yellow border reduces opt-outs
- Simplicity beats complexity in consent interfaces
- Left-to-right reading order decreases performance by 2%
Optimization Impact:
- +127% opt-in rate increase (15% → 34%)
- -63% opt-out rate reduction (26% → 9.6%)
- 5 test cycles to reach optimal configuration
- Test 5 (November) delivered best overall performance
Results
+127%
Opt-in Rate Increase
-63%
Opt-out Rate Reduction
34%
Final Opt-in Rate
56.4%
Not Given Choice Rate
