In fact, all but four of the retailers saw lower customer satisfaction than they had last spring. Overall satisfaction during the holiday season was down 4 percent from last spring, dropping to 73.5 from 76.7 on the ACSI's 100-point scale, said Larry Freed, president of Ann Arbor, Mich.-based ForeSee Results, an ACSI sponsor.

The highest-scoring retailers in the group during the holidays were Netflix, with a score of 84; Amazon, which got an 82; and L.L. Bean and QVC, both of which had scores of 80, according to the study.

Any retailer with a score over 80, which is considered excellent, is doing something right, Freed said. Even so, each of those retailers had lower scores than in the spring -- a troubling trend, he said.

The causes of the decline are twofold: Retailers were unable to satisfy first-time and infrequent visitors to their Web sites, and customers expect better service over the holidays than during the rest of the year, Freed said.

"At first, I was a little surprised by it," he said. "But as we started to look at the data and started to do the analysis, it makes a lot of sense. What we see in the holiday season are a couple things that have a downward pressure on satisfaction. The first is that consumer expectation is high. Their anxiety is high, their deadlines are firm, so holiday shopping is a challenge -- and it's magnified by the challenges retailers often have with inventory. With the hot products of the year, if you can't get them, it frustrates you and it drives satisfaction down.