Amazon (is) selling everything from garden appliances and apparel to electronics and used books. But bigger isn't always better from a customer's viewpoint.

The downward trend is due to consumers' increased expectations during the holiday season, a much larger influx of infrequent visitors that may not know how to navigate a site and shipping costs, and the unavailability of prominent items like the Xbox 360 due to low inventory.

Keeping shoppers happy while they are on the site is just one piece of the satisfaction equation. A bad experience with fulfillment or customer service could outweigh a positive experience on the site.

We're already seeing that shoppers are more likely to return to the site than they were last week and more likely to purchase offline. This is a positive sign for retailers.

The days leading up to the holiday pose a huge challenge for online retailers, who haven't yet figured out how to maintain high customer satisfaction during this critical juncture.

Going forward, we would expect to see satisfaction trend back upward now that the holiday rush is over.