Vodafone A/B test (2021): 31% LCP improvement → 8% more sales, 15% better lead-rate, 11% better cart-rate
Claim: Vodafone A/B-tested an LCP optimization. Result: 31% LCP improvement → 8% more sales, 15% lead-rate lift, 11% cart-rate lift.
Source: https://web.dev/case-studies/vodafone (2021, still cited in 2025+).
Confidence: Verified.
Why this is the cleanest causal evidence: Most "performance affects revenue" claims are correlational. The Vodafone study was a controlled A/B test of a single LCP intervention, with proper isolation. It's the cleanest "do this and revenue moves" data point in the public CWV literature.
Pairs with Deloitte/Google "Milliseconds Make Millions" (2020): 0.1s improvement → 8.4% retail conversion lift, 10.1% travel (industry-wide measurement of 0.1s improvements → conversion lift), Pinterest PWA rebuild (2017, foundational): 60% faster → +40% conversions, +40% time spent, +44% ad revenue (60% faster → +40% conversions), Walmart (2012, foundational): 100ms improvement = 1% incremental revenue; 1s improvement = 2% conversion increase (100ms = 1% incremental revenue), and BBC: lost 10% of users for every additional second the site took to load (10% user loss per added second).
Referenced by (7)
- reference Deloitte/Google "Milliseconds Make Millions" (2020): 0.1s improvement → 8.4% retail conversion lift, 10.1% travel relates-to
- reference Pinterest PWA rebuild (2017, foundational): 60% faster → +40% conversions, +40% time spent, +44% ad revenue relates-to
- reference Walmart (2012, foundational): 100ms improvement = 1% incremental revenue; 1s improvement = 2% conversion increase relates-to
- reference BBC: lost 10% of users for every additional second the site took to load relates-to
- reference Research brief: Page Speed as a Moat — why CWV separates the agencies from the freelancers (piece 9 of 15) relates-to
- reference Research brief: Website Performance & Revenue — defensible evidence for KW small-business owners (piece 17) depends-on
- reference Rakuten 24 (2022 A/B test): CWV optimization → +33.13% conversion rate, +53.37% revenue per visitor, -35.12% exit rate relates-to