PistonHeads

Breaking the A/B testing deadlock

Fifty-fifty overall. Until we looked at who was actually buying.

PistonHeads car search case study

The challenge

PistonHeads had a core search decision to make: should users search by a single car model or by several? The A/B test came back inconclusive. With no clear signal, the team was stuck on a business-critical feature.

What I led

I reframed the question from "which version wins?" to "which users matter most, and what do they need?" I designed a survey that separated what users said they preferred from how they actually behaved, then cross-referenced it with site usage and sales data to profile the highest-value segment. I presented the findings to the product team as a clear recommendation.

The outcome

The test had averaged everyone together. Split by value, the picture was clear: users who wanted single-model search were more experienced on the site, more likely to buy and worth more over time. Designing for them, rather than for the average user, gave the product team a direction it could defend with commercial evidence rather than opinion.

Where this fits

This is the work of the Fractional Insight Lead: when the numbers alone can't settle a decision, find out whose behaviour matters most.

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