Social proof should not be a “set and forget” effort. Most retailers and brands see the largest ROI when they extend social proof across the customer journey. For Castore, the numbers tell the story.
The premium sportswear brand, founded in Liverpool in 2016 and now the official kit partner to England Rugby, Rangers and Harlequins, had already proven the case. Its first test of Taggstar’s Social Proof Pro Plan, running across the PDP and cart, delivered a 1.51% conversion rate uplift in just 15 days.
In Q1 2026, Castore extended social proof messaging to the product listing page to engage shoppers earlier in the purchase journey. Two new messages, ‘In Demand’ and ‘Great Choice’, went live on the PLP, bringing all seven Pro Plan messages into play across a full-funnel test.
The result, over 45 days in the UK: a further 2.07% conversion rate uplift on top of earlier gains, and £30,933 in incremental revenue.
That’s the compounding logic of full-funnel social proof. The PDP turns hesitation into purchase. The PLP gets the right products in front of shoppers in the first place. Together, they guide customers through every stage of the decision, not just the final one at the point of checkout.
“After the great results of the first test, it was a natural progression for us to launch social proof messaging on the PLP.” — Kirsty Ashworth, Head of eCommerce, Castore.
The results, Castore reports, beat expectations.
Next on the joint roadmap is a power phrases test, comparing phrases such as ‘Going Fast’ with those supported by additional sales volume data, such as ‘Going Fast, 26 people have it in their bag RN’, to see what resonates most with a premium audience.
The takeaway for eCommerce teams: social proof earns its place across the funnel, not just on the product page. The earlier you guide the decision, the better results you’ll get.
