Telefónica Deutschland, headquartered in Munich and serving about 35 million active cell phone contracts under its o2 brand, partnered with e-dialog to deploy Vertex AI Search for Commerce on the Google Cloud Platform. An A/B test showed a 17% click-through rate on personalized banners, a 275% conversion-rate uplift in the hero use case, 939% ROI, and 40 million calculated recommendations in the first 30 days of full production.
The deployment, branded internally as OREO (On-site Recommendation Experience Optimization), fixed a structural problem in the legacy recommender: standard quotes and manually maintained rule-based logic could not respond to mid-session intent shifts, for example when a user moved from Apple to Samsung devices. The new system had to meet four criteria: work without users logging in, interpret browsing behavior with zero latency, automatically identify the highest purchase probability, and lift revenue without manual effort.
Implementation followed two phases. In the pilot (Phase 1), e-dialog deployed a lean MVP for accessory recommendations ("Frequently bought together") on product detail pages. Previously, specialists entered rankings into Excel, converted them to JSON, and uploaded them, leaving recommendations stale. e-dialog automated the MVP by combining Google Analytics behavioral data with up-to-date product-feed data into continuous streams; the Vertex AI Retail API ranked products fully automatically and delivered dynamic JSON output. Even this first step eliminated manual effort and lifted online-store conversions by 66%, with ROI above 550%.
In Phase 2, the team scaled to the hero use case: banner personalization on the homepage's most prominent ad spaces, powered by Vertex AI Recommendations and driven by real-time session data. Defining the infrastructure as Infrastructure as Code (IaC) and integrating it into an automated CI/CD pipeline made it fully auditable and reproducible across other brands. e-dialog also combined the onsite AI with Google Ads strategies, including Performance Max and Demand Gen, creating a closed-loop ecosystem in which media signals flow directly into onsite personalization.
The engine runs entirely without user login by leveraging anonymized in-session clickstream signals. According to Steven Burkhardt, Head of Digital Analytics & Performance Management at Telefónica Deutschland, with Vertex AI Recommendations the team now delivers personalized recommendations in real time that instantly adapt to user behavior and reliably drive conversions. The engine is fully automated in production, with e-dialog continuing to operate the architecture and run optimization cycles.
Telefónica Deutschland's long-term goal is comprehensive page-level optimization, in which AI models individually arrange the entire page layout. The OREO infrastructure is positioned as the foundation for that expansion, with browsing preferences available in real time across the Mein O₂ app, in-store retail, and the service hotline as future omnichannel touchpoints.