Customer data expert dunnhumby, is out with its second annual Retailer Preference Index (RPI), which it says “surveyed 7,000 U.S. households to determine which of the top 56 largest grocery retailers have the strongest combination of financial performance and consumer emotional sentiment.”

According to the results, Trader Joe’s was again the top-rated grocery retailer.

The grocery retailers with the highest overall consumer preference index scores are: 1) Trader Joe’s, 2) Costco Wholesale, 3) Amazon, 4) H-E-B, 5) Wegmans Food Markets, 6) Market Basket, 7) Sam’s Club, 8) Sprouts Farmers Markets, 9) WinCo Foods, 10) Walmart, 11) Aldi, 12) Peapod, 13) The Fresh Market.

Here’s the dunnhumby analysis of what earned Trader Joe’s the top spot for the second year in a row:

“Trader Joe’s is a prime example of a retailer making trade-offs to deliver superior Value … With its small format, lack of digital shopping and limited national brand offering, the retailer focuses on speed of in-store shopping and having a rich Private Brand offering.

‘This bricks-and-mortar only, private brand approach minimizes costs and keep prices low, allowing them to reinvest in customer service, product quality and in-store experience.

“This strategy sacrifices reaching customers through a growing digital channel and breadth of assortment, and therefore losing on one-stop shop-ability and convenience. However, this loss is also their gain since it allows them to deliver what matters most to their customers.”

And, dunnhumby makes the following broader observation:

Retailers that ramp up investment in digital must be cautious not to take their eye off the retail basics. Some retailers have achieved an excellent digital customer experience, but their financial performance has not benefited, while others with a focus on digital manage to thrive. Retailers missing any of the following are not maximizing the impact of digital investment: large scale, great price perception and a category DNA leaning toward center store items and non-grocery products.

KC's View: I’m willing to accept the dunnhumby analysis, though I’m not quite buying its conclusions … mostly because I’m always skeptical about “nation’s best grocery store” studies.

They’re just not fair, since not everybody has access to the same stores, and supermarkets can be so different in style and purpose - with entirely differentiated customer bases - that comparing them is kind of silly.

I mean, I’m not sure that Wegmans and WinCo belong on the same list - they operate in different parts of the country, have vastly different strategies and tactics, and appeal to entirely different people.

I also think it is a mistake to limit such studies only to “large” companies, since it often is smaller, independent stores that foster the strongest consumer emotional sentiments.

Is Trader Joe’s a terrific store? Sure. For what it is. But would I feel a stronger emotional connection to it than to a Dorothy Lane Market or a Lunds & Byerlys or a Metropolitan Market or a Westborn Market or a bunch of other grocers I could name, if I could shop at any or all of them?

I think not.