When it comes to customer satisfaction, retailers might need to step up their game.

According to the American Customer Satisfaction Index, which tracks consumer evaluations on products and services across the U.S., overall customer satisfaction with retail is down for the second year in a row, dropping 0.9 percent to 77.4 on the index’s 100-point scale.

The report — which covers six retail categories including department and discount stores, specialty retail stores and internet-based shops — registered a widespread but modest decline in the industry. (The index analyzed data from interviews with about 300,000 customers on more than 400 companies across 46 industries.)

Although customers are increasingly turning to online shopping sources, the ACSI’s results also indicate a decrease in the level of customer satisfaction in e-commerce, which dipped 2.4 percent in the past year.

“There is a slump in customer satisfaction in every category of the retail sector,” managing director David VanAmburg said in a statement. “Internet retail versus brick-and-mortar retail, department stores versus specialty stores — it’s all down. Considering the importance of retail to overall consumer spending, this decline is a big deal.”

Disappointing customer service has been cited as one of the reasons for the downtrend. As the economy boasts low unemployment rates, retailers are scrambling to find qualified candidates for open roles, manage staff shortages and deal with employee turnover — all factors that put a strain on customer service.

“Historically, the ACSI has found that the more service typically required for a given industry, the lower the customer satisfaction, and it rings true for retailers this year,” VanAmburg added. “Things like courtesy and helpfulness of store staff, call center support and even availability of merchandise on the shelves all have a service element and have seen drops from a year ago.”

By category, the ACSI noted that department and discount stores saw customer satisfaction slide 1.3 percent to a score of 76 amid digital disruption and the struggle to adapt to in-store expectations. Despite early U.S. holiday retail sales data painting a more hopeful picture for such businesses, a number of big-name chains including Macy’s, J.C. Penney, Kohl’s and Target posted weaker-than-anticipated results during last year’s final two-month stretch.

Numbers from the customer satisfaction index show Macy’s and Target unchanged at 77 points. Although also at a score of 77, J.C. Penney saw a decrease of 3 percent, while Nordstrom shed 2 percent to 79. Kohl’s remained stable, ranking at 79. The ailing Sears, however, came in last place, falling 4 percent to an all-time low of 70 points, with respondents pointing out the lack in merchandise selection and locations as the company shutters more stores in the face of bankruptcy.

Separately, specialty retail stores were down 1.3 percent to 78 points. L Brands, parent company of the now-retired Henri Bendel brand, Victoria’s Secret and other popular mall brands, kept its first-place spot at 82 despite retreating 4 percent. A number of other stores were deadlocked at the category average of 78, including Foot Locker (unchanged) and Gap (1 percent gain). On the other hand, Dick’s Sporting Goods teetered at the bottom of the pack, dropping 4 percent to 74. The outdoor and athletic retailer made headlines last year with its decision to ban assault-style rifles in stores and raise the minimum age for gun buyers to 21, becoming one of the first major national chains to make adjustments to its gun policy following the Feb. 14 massacre at Marjory Stoneman Douglas High School in Parkland, Fla. (The retailer’s decision has received widespread support across social media, but the firm has also reported a hit to revenues stemming from its pullback on the sale of certain firearms.)

Perhaps another surprising finding is Costco’s dominance over eight-year leader Amazon, with a score of 83 in customer satisfaction versus the e-commerce behemoth’s 4 percent drop to 82. The membership-only warehouse operation joins the index’s internet retail category for the first time, along with Nordstrom, Kohl’s and Nike — all tied at 81 points. Target and Macy’s managed to make the category average of 80, while Walmart and Sears anchored the bottom at a respective 74 and 73 points for their online enterprises.

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