When it comes to understanding customer satisfaction, it’s best to go straight to the source: the customers themselves. Perhaps no one does that better than the American Customer Satisfaction Index, a research groups that looks at more than four dozen industries to find out what customers are buying and how satisfied they are with their experiences.

ACSI’s data covers all major consumer industries. With data from the last 20-plus years, the organization can see how trends and technology impact overall customer satisfaction. The biggest trend in retail for 2018 is the continued growth of online retailers and the struggle of traditional big-box retailers, said ACSI Managing Director David VanAmburg.

Brick-and-mortar stores have been struggling for quite some time, especially as online stores like Amazon and Walmart continue to grow. However, the struggle has been bigger in the past year compared to the previous three to four years. It’s even harder for specialty mall stores like Gap to find their footing with customers. Customers just aren’t shopping in malls as much anymore, which means many of these stores have had to focus on their online presence.

A great example of that is Nordstrom, which is doing better than many other department stores. Nordstrom saw that the industry was changing a few years ago and pivoted to expand its web presence. The idea is to be where the customers are. Nordstrom realized many of its customers prefer shopping online, so it put more effort into its online experience. VanAmburg says one of the keys to a strong web shopping experience is navigation. It should be intuitive for customers to find what they want. There also has to be logistics to match—even a great website doesn’t create satisfied customers if the items or sizes they want aren’t in stock.

For modern customers, efficiency and convenience is crucial. That’s one of the reasons that supermarkets and drug stores are doing better than they were a year ago. As Amazon moves into the space with its Whole Foods acquisition, supermarkets have improved their marketing and found ways to offer competitive convenience. Even small changes to the look and flow of the store can improve efficiency and overall customer satisfaction. ACSI’s data has found that efficiency is the most important quality to customers. In a world where Amazon offers two-day shipping and instant in-store checkout, stores have to come up with creative ways to compete.

In order to get customer data that is useful, stores must focus on the entire customer experience. ACSI regularly asks customers about all of the elements of the shopping experience, from overall satisfaction to their expectations, prices, store location, employees, and merchandise. Customer satisfaction doesn’t some from one single area, but is the totality of the entire experience. Stores can use the same metrics to track their own internal progress and that of the competition.

Today’s world is data-driven, and customer satisfaction is no exception. In order to best serve customers and compete with the retail giants, stores across all industries need to understand customers and what they are looking for. With the help of ACSI and other internal data, retailers can stay ahead of the competition.