(NBC) -- We all have a favorite supermarket. What's yours? Would you recommend it to a friend?
When 6,600 shoppers in the U.S. and Canada were asked those questions recently, they picked Trader Joe's. It rated 4.8 out of 5 for customer satisfaction.
Trader Joe's is a small national chain. Each of the nearly 400 stores has the feel of a neighborhood store with great service and a variety of private-label products.
Publix Supermarkets and Whole Foods Market were close behind in the ratings. All three earned high marks for courteous staff, inviting atmosphere and high quality produce.
The survey, conducted by Market Force Information, was designed to find out why people prefer one chain over another. The researchers found that by and large, the industry is doing a good job, with an overall satisfaction rating of 4.3 out of 5. Even Wal-Mart, the lowest-rated chain, earned a 3.9.
"Most of us are pretty happy with our supermarket," said Janet Eden-Harris, chief marketing officer at Market Force Information. "But there are a handful of chains that really stand out, that delight everybody."
What makes a store your go-to grocery store?
The number one factor is convenient location, then low price and good sales/promotions. But that doesn't tell the whole story.
"Those are the basics," Eden-Harris told me. "You better offer them to me or I'm not even going to go into your store."
To stand out from the crowd and take customers away from the competition, a supermarket chain must provide what Eden-Harris calls "operations-related attributes." These include: fast check-outs, friendly staff and cleanliness, as well as good private label brands and high-quality meat and produce.
And the winners for operational excellence are:
Whole Foods was the clear winner for high-quality meat, high-quality produce and natural/organic choices
Trader Joe's ranked first for atmosphere, quick checkout and private label brands, second for cleanliness and natural/organic choices
Publix was top-rated for cleanliness and courteous staff, second for high-quality produce
Costco came in second for high-quality meat
Many grocery chains are regional, so Market Force broke out its results into four U.S. regions and Canada. Shoppers were asked where they spent the majority of their grocery dollars during the past 30 days. Because Wal-Mart dominates the country, it was omitted from the regional analysis. The favorites were:
Northeast: Stop & Shop (11%), GIANT (6%), Wegmans and Market Basket (tied at 5%)
South: Kroger (16%), Publix (15%) and H-E-B (5%)
Midwest: Kroger (11%), Meijer (9%) and Hy-Vee (8%)
West: Safeway (12%), Kroger (9%) and Costco (7%)
Canada: Loblaws (15%), Sobeys (11%), Costco and Safeway (tied at 7%)
(Read: full report for more specifics on how chains rated)
Better be on your game if you want my business
The average shopper goes to the supermarket about twice a week. And we don't want to waste time while we're there.
The Market Force survey makes it clear people don't like to wait in line at checkout and they get frustrated when they can't find the products they want.
If they're not happy, if they aren't treated the way they expect to be, they'll take their business elsewhere.
"There's more focus on service quality and the customer experience these days because you can only compete strictly on price and selection for so long," said Andrew Baker, a marketing professor at San Diego State University.
And he points out, if your experience is pleasant, the inconvenience of going to the store becomes more tolerable.
"And as a result, you may spend more time perusing the aisles and that means there's more opportunity to stray from your shopping list and purchase additional products," Baker said.
So what happened to extreme couponing?
The shoppers in this survey - 60 percent of whom had a household income of more than $50,000 -said they're not using coupons or promotional offers as much as they did last year. And the drop is significant.
Fewer people are using newspaper coupons, online coupons, even coupons given out by the store. Slightly more than 20 percent said than had not used a coupon at the grocery store in the last 30 days. That's up from about 15 percent in 2011.
Janet Eden-Harris told me she was "really surprised" by the continued drop in coupon use.
"There's been a downward trend year after year for three years and this was definitely the lowest of the last three years."
Why? They didn't ask that, but she speculates it might be that people are a little less worried about the economy and not pinching pennies as much.
The supermarket industry is well aware of this. In its 2012 U.S. Grocery Shopper Trends report, the Food Marketing Institute made it clear that "changing the in-store experience" is critical to the industry's long-term success.
"We can't just keep putting more in the store. We must both display it better as well as help simplify the overall in-store experience," the report stated. "We have to rethink merchandising from items to ideas. Historically we sold our shoppers merchandise to fill their pantries. They are now asking us for help in understanding how to live better lives."