When people talk about CRO (Conversion Rate Optimisation), it's usually framed as a modern, digital discipline. A/B testing, heatmaps, analytics tools — it all feels very "online".
But in reality, the principles behind CRO have existed for over a century. At its core, CRO is about understanding how people make decisions, removing friction, and improving how value is communicated. The best marketers and retailers have been doing this long before websites ever existed.
Paco Underhill — Customer Behaviour in Physical Retail
A great example comes from retail anthropologist Paco Underhill, author of Why We Buy — one of my favourite reads on this subject. Through observing real in-store behaviour, he identified patterns that retailers could use to improve performance.
He found that shoppers naturally behave in predictable ways — most people tend to turn right when entering a store, and they're far less likely to engage with products if the environment feels cluttered or overwhelming. Small changes like improving store layout or making products more visible had a direct impact on customer behaviour.
These weren't just design improvements — they were conversion improvements. By reducing friction and improving the experience, retailers saw more customers browsing, engaging, and ultimately buying.
Claude Hopkins — Making Value Clearer to Increase Conversion
Another strong example comes from early advertising pioneer Claude Hopkins, who worked with brands such as Schlitz Brewing Company. Hopkins didn't change the product itself — instead, he changed how it was communicated.
He focused on clearly explaining how the beer was made, highlighting quality, cleanliness, and production methods. The idea was simple: remove doubt and build trust by being transparent. The result was a significant increase in sales — by making the value clearer and more tangible, more customers felt confident enough to buy.
This is exactly what CRO does today — just in a different format. Improving clarity, reducing uncertainty, and helping customers make decisions faster.
More Pioneers Who Got There Before Digital
Testing, Packaging & In-Store Optimisation
P&G continuously refined how products were positioned and presented based on how customers responded in real environments. Small changes in packaging or placement led to noticeable improvements in sales — the same logic as modern A/B testing.
Emotional Messaging & Consumer Trust
J&J focused heavily on consumer trust and emotional messaging, testing different approaches to understand what resonated most with their audience. Even subtle changes in how a product was described could influence whether someone chose to buy.
Optimising the Sales Experience
Ford optimised everything from showroom layouts to sales processes to improve the likelihood of a customer making a purchase — including how vehicles were displayed, how sales conversations were structured, and how the overall buying experience felt.
The Evolution of CRO
What all of these examples show is that CRO is not new. The tools have changed — from store layouts and print ads to websites and apps — but the fundamentals remain exactly the same.
At its core, CRO is about understanding customer behaviour, identifying friction, and making it easier for people to say yes.
Why aren't more people converting?
The best practitioners today aren't just analysts or testers — they're people who think commercially, understand behaviour, and are constantly asking this question. Because whether it's a store, a print ad, or a digital experience, conversion has always been the goal.