Rakuten 24 (2022 A/B test): CWV optimization → +33.13% conversion rate, +53.37% revenue per visitor, -35.12% exit rate

Claim: Rakuten 24 (Japan) ran an A/B test in 2022 optimizing Core Web Vitals: CLS improved 92.7%, FID 7.95%, FCP 8.45%, TTFB 18.03%, ~0.4s LCP gain.

Outcome: +33.13% conversion rate, +53.37% revenue per visitor, -35.12% exit-rate reduction.

Source: web.dev/case-studies/rakuten (2022).

Methodology: true A/B test — only change between variants was performance.

Confidence: High (performance is cleanly isolated).

Use in sales conversations: this is one of the strongest "performance changes only" lift numbers in published literature. Pair with Vodafone A/B test (2021): 31% LCP improvement → 8% more sales, 15% better lead-rate, 11% better cart-rate and redBus (2023): INP improved ~72% on search page → +7% sales (6-7.2% CR uplift across operating countries) for a three-case A/B-test cluster.