Intuition and proof are very different things. Does it make sense that a well-designed store will achieve higher sales than a tired interior? Of course. If that store is appropriately and interestingly illuminated, then it also makes sense that the store will bolster sales and attract more repeat visits. Again, common sense.
Next, let’s factor in the economy, the location, consumer trends, pricing and promotions, the time of year, the fluctuating price of petrol, unseasonable weather, a big sporting event on the TV, a retailer’s advertising campaign, good or poor customer services, shelf availability, how the bank holidays fall, and so on. So what was the financial uplift in sales specifically through lighting again?
Munish Datta, head of facilities management at M&S, which recently embarked on a big LED rollout at hundreds of its food stores, said that the benefits of increased sales could ultimately outweigh the savings from energy efficiency. But how will they know?
Simon Waldron, electrical engineering manager at Sainsbury’s, an LED advocate within an LED-advanced retailer, admits: ‘There’s this big discussion at the moment about whether LEDs increase sales. We cannot guarantee that LEDs are a primary cause of any sales increase because there are so many variables. At the moment there’s no significant empirical data that suggests LEDs have any impact on sales. There need to be more studies done to see whether LED lighting or specifically higher CRI products, actually has the benefit of increasing sales in a store.’
Lighting by numbers
Anyone who can prove that a new lighting scheme will save money from the bottom line and increase sales on the top line has a powerfully persuasive argument and so not surprisingly there have been numerous attempts to do it.
Among these was a 21-week field research project by Dutch co-operative supermarket group Plus and Philips Lighting back in 2010. Using different LED-based lighting scenarios, the study was designed to measure the impact of light on customer buying behavior and Philips Lighting enlisted CQM as an external market research agency and the Retail Design Research Lab of the PHL University of Hasselt to evaluate the return on investment for retailers from implementing LED lighting solutions. A tracking system was installed in shoppers’ grocery baskets, to trace shopping habits such as the time spent in certain parts of the supermarket, their route around the store and parts of the shop they were drawn to specifically.
AmbiScene-controlled lighting was fitted on the left-hand side of the store, while the right-hand area of the supermarket was lit with traditional lighting and different lighting scenarios were applied over alternating days.
The results from CQM showed that the introduction of the lighting system increased basket sales, with the average sales per customer up by
1.93 per cent related to the dynamic lighting installation. Further analysis of the results also showed that customers spent more time in the areas lit with warmer light settings than those with cooler ones.
Lighting manufacturer Zumtobel also reckons it has an answer to the question of whether lighting can boost sales.
Zumtobel claims a fashion retailer in Germany saw its sales go up by around 12 per cent compared to another local store, after it installed a new lighting scheme specially designed to appeal to the personality profile of its target customers.
But it's hard to know what other factors affected the two stores, or what would have happened if the lighting had stayed the same.
Zumtobel conducted another piece of research entitled ‘Attention, attractiveness and perception mediated by lighting in retail spaces’. Its two-part study with Prof Jan Ejhed, head of the lighting laboratory at the Royal Institute of Technology (KTH) in Stockholm, and Dr Roland Greule from the Hamburg University of Applied Sciences (HAW) came to eight key conclusions (see box, right), which broadly reflect the way that many better-lit stores now approach their lighting strategy.
Point of sale
A further laboratory study conducted by Zumtobel and Gruppe Nymphenburg measured responses to various lighting scenarios in shops on an empirical basis. ‘Again and again we find that the importance of lighting at the point of sale is dramatically underestimated. Instead, the focus is on fancy packaging and shop design,’ says Dr Hans-Georg Häusel of Gruppe Nymphenburg. ‘But actually, the goods on display will only touch people’s emotions if they are presented in the right light.’
On top of that, results from a study conducted for Xicato by independent lighting researcher Dr Colette Knight found that objects can appear more attractive under a light source that is slightly outside the traditional colour range for white light.
Participants in the study showed a strong preference for lights which increase the saturation of reds, blues and pinks and make whites appear ‘cleaner’.
Knight’s report concluded: ‘With the maturity of LED lighting, there is now growing focus to look beyond mimicking the light properties of conventional sources… By cleverly designing the light spectrum, it is possible to generate various light impressions and optimise the colour appearance of objects.’
These bodies of work add to the argument for good lighting, but turning browsers into buyers is the challenge. That said, retailers are increasingly looking to differentiate their stores and as Rod Pallister of Progress Lighting, reflects: ‘Evidence or not, high street retail is having to become more creative and provide experiences to retain or win new custom.’
He points to the growth in leisure and entertainment aligned with retail destinations.
‘If you look at most new shopping centres, they are all about retaining custom and keeping us all engaged for longer. Most have bars, cinemas, restaurants as well as shops,’ he says. ‘They take an architectural approach to the whole design and you cannot say lighting does not play a vital role in bringing the design together.’