Discover How Easily You Can Maximize ROI with Offsite Retail Media in Google Ads

The retail media domain is experiencing a massive transformation as brands come to realize the vast, unexploited opportunities within offsite retail media. With Google’s recent launch of the dedicated Google Code Gateway for advertisers, marketers now have a powerful tool to enhance conversion tracking, optimize AI-driven campaigns, and leverage first-party data more effectively. In APAC, where e-commerce thrives, early adopters are achieving an average 5X return on ad spend through offsite strategies, a stark contrast to traditional onsite approaches. Rakuten Ichiba's groundbreaking research reveals just 4% overlap between onsite and offsite buyers, proving these channels reach fundamentally different audiences. This divergence mirrors Fielmann's digital transformation journey, where combining YouTube's Demand Gen campaigns with Google AI drove a 7.7% lift in purchase intent alongside 24% higher "Add to Cart" conversions, is the right choice in Google Ads. As consumers fluidly move between streaming, scrolling, searching and shopping—what BCG terms 4S behavior—offsite retail media emerges as the connective tissue binding fragmented customer journeys.

I. Leveraging Rakuten’s First-Party Data for Optimal Targeting

The magic of Rakuten's offsite solution lies in its consented first-party data architecture, which enables surgical audience segmentation while respecting privacy boundaries. When integrated with Google Ads, this data goldmine reveals surprising behavioral patterns—shoppers who engage with offsite ads frequently purchase complementary items beyond their initial click. Rakuten Promotion Platform Expansion demonstrates how retailer-supplied purchase signals can optimize Search and Shopping Ads beyond the host platform. This approach mirrors Google's AI-powered audience expansion for Fielmann, which successfully reached younger demographics and female shoppers previously untapped by traditional campaigns. The technical backbone—similar to Google's new Code Gateway for advertisers—ensures accurate conversion tracking across domains while maintaining data security through encrypted server-side transmissions.

II. Strategic Campaign Design for Maximum ROI

Rakuten and Google's joint experiments with 44 advertisers overturned conventional wisdom about retail media tactics. Counterintuitively, ads featuring diverse product catalogs outperformed selective high-margin item promotions, as customers appreciated discovering related products. Budget allocation followed a similar nonlinear pattern—exceeding break-even thresholds by doubling daily budgets relative to product prices generated exponential returns. These findings align with Kantar's pricing elasticity research showing strong brands can command premium pricing through strategic marketing investments. The experiments proved that consistent application of these principles sustains growth beyond peak periods, unlike temporary promotional spikes that Fielmann overcame through always-on Demand Gen campaigns in Google Ads.

III. AI-Driven Optimization in Offsite Retail Media

Google's AI tools transformed Rakuten's campaigns through three key mechanisms: automated audience expansion, dynamic creative optimization, and predictive budget pacing. The AI identified lookalike audiences with 11% greater efficiency after implementing first-party data enhancements, similar to performance lifts observed with Google's advertiser-specific code gateway. However, as Fielmann's team discovered, human oversight remains crucial—their creative team used AI to rapidly generate YouTube Shorts variants while maintaining brand consistency through rigorous review protocols in Google Advertising. This hybrid approach delivered 50% lower CPMs on incremental reach compared to traditional video buys. The AI's ability to analyze cross-channel signals (like Rakuten's onsite/offsite data interplay) created a virtuous cycle where each campaign iteration improved targeting precision in Google Ads.

IV. Measuring Success Beyond Immediate Conversions

Unified Lift studies revealed offsite retail media's hidden benefits—brands employing Rakuten's solution saw 60% higher branded search volume alongside direct conversions. This dual impact mirrors Fielmann's experience where Demand Gen in Google Advertising simultaneously boosted upper-funnel metrics (7.7% purchase intent lift) and lower-funnel actions (24% cart additions). Kantar's pricing elasticity models quantify this halo effect—every 10% reduction in elasticity enables 14% price increases with just 7% volume decline, translating to 7% revenue growth. Rakuten's advertisers achieved similar compounded value, where initial purchasers from offsite ads demonstrated higher lifetime value through repeat buying—a phenomenon measurable through Google's enhanced conversion tracking.

V. Overcoming Common Challenges in Implementation

The path to offsite retail media success requires breaking organizational silos—a lesson Fielmann learned when restructuring its content production teams to unify upper/lower-funnel efforts. Rakuten's solution addresses technical barriers through seamless Google Ads integration, but brands must still reconcile disparate data systems. Google's evolving AI tools present both opportunity and complexity—while Performance Max campaigns automate cross-channel bidding, they demand rigorous first-party data infrastructure like the new Code Gateway to function optimally. Legal considerations around AI-generated content (as highlighted in Google's creative compliance guidelines) necessitate human review layers without stifling automation's scalability benefits.

Privacy-centric tools are critical for sustaining data flows, and Topkee addresses this through server-side tracking via TTO, which associates multiple tag IDs for accurate data attribution while adhering to consent mode requirements. The platform’s TM settings offer advanced UTM-like tracking with customizable rules for granular campaign monitoring, ensuring compliance without sacrificing performance insights. The elastic budget structures are enabled by Topkee’s ad reporting analysis, which evaluates ROI, conversion quality, and cost-per-acquisition to dynamically adjust bids and keyword strategies.

VI. Future-Proofing Offsite Retail Media Strategies with Google Ads

Forward-thinking brands are adopting Rakuten's always-on approach, recognizing that continuous optimization outperforms seasonal bursts. The next frontier involves integrating retail media with full-funnel tactics—combining Rakuten's granular product data with YouTube's storytelling power as Fielmann demonstrated. Emerging solutions like Performance Max for Marketplaces will further blur channel boundaries, while privacy-centric tools (server-side tracking, consent mode) ensure sustainable data flows. Brands replicating Rakuten's success should focus on three pillars: robust first-party data systems, AI-human collaboration frameworks, and elastic budget structures that scale with proven performance, all of which can be enhanced through effective use of Google Advertising. These principles that helped Kantar's cosmetic client achieve 76% revenue growth from marketing-driven pricing power.

Topkee’s keyword research tools identify high-intent search terms, while smart bidding and broad matching expand reach without diluting relevance. Remarketing campaigns by retargeting users based on their interaction history, using TTO’s attribution insights to trigger contextually relevant ads. Ultimately, Topkee’s holistic approach—spanning website SEO assessments, automated TTO workflows, and cross-channel PMax deployments. By unifying data, creativity, and budget flexibility under privacy-compliant frameworks, brands can achieve sustainable growth.

Conclusion

The Rakuten-Google partnership, particularly within the realm of Google Ads, proves offsite retail media isn't just an extension of onsite tactics—it's a fundamentally different growth engine that captures untapped audiences throughout their 4S behavioral loops. By combining consented retailer data with AI optimization and cross-channel measurement, brands can achieve the elusive trifecta: immediate conversions, lasting brand equity, and pricing power. As these tools evolve—from Performance Max to advertiser-specific code gateways—the competitive divide will widen between brands leveraging this holistic approach and those stuck in channel-specific silos. For organizations seeking guidance in navigating this complex landscape, consulting with retail media specialists can accelerate time-to-value while avoiding common implementation pitfalls.

Appendix: 

1. Rakuten's Offsite Retail Media Solution
2. Fielmann's Demand Gen Case Study
3. Kantar's Pricing Elasticity Research
4. Google AI Marketing Guidelines