B&Q has increased sales on its website by more than £3m in the past year through a programme to optimise its conversion rates.

Working with EMC Consulting, the DIY retailer has run multivariate testing on its site for the past year, since the site relaunched, to continually optimise the user experience.

B&Q multichannel development manager Jo Robb said that every test has produced a positive result in terms of conversion uplift. Since March 2009 the retailer has increased its checkout conversion rate by 4% and reserve-and-collect conversion by 7% - which has paid for the cost of the testing programme many times over.

The testing began with optimising the look and feel of pages closest to the conversion point - such as the checkout page - and B&Q has worked backwards from there.

Robb added that it is often not possible to explain why small changes to text, colours or the layout of pages makes a difference to conversion, and the retailer has just accepted what it has learnt and worked with it.

One counter-intuitive change that has been made as a result of the testing is to give less prominence to a button that allows customers to update their shopping list, as B&Q found this actually improved the conversion rate.