"We find a third of all our experiments are positive, a third are flat, and a third fail," he said.
When the company moves to increase the number of monthly experiments, Hornby cited the low success rates of Google's internal tech experiments to explain why he expects the proportion of successful experiments to fall.
In the past, the company sub-contracted a validation lab study one to three times a year.
As part of its digital transformation, one of the most recent investments that Shop Direct made to support its experimental and customer-centric culture was the building of a £100,000 user experience lab right in the heart of its headquarters, which opened in January.
The lab, which is set up like a living room, with cameras, eye-tracking technology and double-sided mirrors, is where Shop Direct invites customers to come into each fortnight "to get under the skin of how customers respond to new things that we do," said Hornby. One lab study is carried out every other week alongside split testing of the website.
Other investments that Shop Direct made as part of its digital transformation were in people and technology.
Hornby heads up an ecommerce team of 65 people, which sits separately from IT. This is up from just 10 people in ecommerce in 2006.
"We invested in front end development skills, how to be more agile, interactive design, how to design things with the customer at the heart, and usability, how to get physically close to the customer," he said.
He also said that Shop Direct's "biggest and most successful" investment was made on replatforming on Oracle.
"We were originally on a home-grown, not fit-for-purpose platform. We use Oracle ATG Web commerce, which provides the solid foundation we needed to support everything on top," he said.
Shop Direct also works with a number of smaller companies, including a start-up called Qubit, which provides an integrated platform for tag management, A/B testing and visitor analytics, personalised display advertising solutions provider myThings and UserZoom, a software to test user experience.
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