New WSU study says grocery stores can trick customers into spending more

Grocery shopping can be frustrating when everything is suddenly rearranged. A new study by two Washington State University researchers said that when stores do this, it makes customers impulsively buy more.

The research started when Gihan Edirisinghe, study lead author and a former WSU Ph.D. student, took a Saturday evening trip to Walmart a few years ago. As he and his wife were shopping they noticed something was off.

“We found ourselves walking the aisles we normally do but all our stuff had moved,” Edirisinghe said. “So, I started wondering if the Walmart folks had put a lot of thought into the rearrangement. When I got home, I checked the literature and it turned out there was a lot of research on one-time store rearrangements but literally nothing data-driven on the best way to periodically rearrange products.”

Edirisinghe shared his thoughts with Chuck Munson, a professor at the WSU Carson College of Business, and they put together a model.

Their model looked at a store’s most profitable products so they could be placed where customers could see them.

Next, it looked at which items were usually bought together so they could be placed in a way that customers would notice something interesting.

Finally, the model used what the researchers call “past-aisle impulse” to take advantage of how familiar a customer was with where products used to be. This could help shape future store layouts.

“This last step is designed so that people looking in a familiar place for, say, potato chips will notice something new that our data tells us will interest them,” Edirisinghe said. “Every rearrangement can then be used as the basis for the next. To the best of our knowledge, no previous research has considered this effect.”

What’s new about their model is that it’s designed to look at what isles customers normally walk down and put new products there. These products are similar to products they bought before and will make customers spend more money, Munson said.

The researchers found that if the store is more like a gas station next to a freeway, where people don’t have a lot of familiarity with the layout, this method of rearranging products wouldn’t have a big effect. However, if the store is more like Whole Foods, where people are very familiar with the layout, rearranging products can make customers spend a lot more, Edirisinghe said.

The researchers said they hope their study will get enough interest from retailers that they can do a real-life test.

“Our allocation method could ultimately be something that store managers could install and use with a little training,” Munson said. “When you take into consideration the fact that 80% of shoppers don’t make a list before visiting a brick-and-mortar retailer, it is easy to see how important something like this could be to maximizing profits and helping physical stores compete with online retailers.”