For some reason, they neglected to mention that Microsoft's own sites have also been found doing EXACTLY THE SAME THING. Weird.

Here is the patent in question.

For those too lazy to click, here's the primary claim:

A method of encouraging customers to provide reviews of purchased items, the method comprising:

receiving over a network an order from a first customer for an item purchased from an electronic catalog;

estimating by what date the first customer will have at least initially evaluated the item based at least on the item type;

initiating an electronic transmission, based at least in part on the estimated date, to the first customer on or after the estimated date of a message requesting the first customer to provide a review of the item to thereby encourage the first customer to provide at least one review, wherein the message includes a link to an electronic review form and activation of the link by the first customer causes the review form to be presented to the first customer;

receiving the review from the first customer electronically via the review form;

individually presenting the first customer review in a group of reviews to a second customer interested in the item; and

based at least in part on the first customer's review, using a collaborative filtering process to automatically generate personalized recommendations for the first customer of other items.

One thing that's common to all the claims is that the system estimates when the user will have evaluated the item, based on what kind of item it is. So if you always send the review request three days after shipping, you're not infringing the patent. OTOH, if you figure that books take longer than DVD's to evaluate, and therefore don't send a book review request for a week, then you may be in trouble.

Also, note that the patent application was filed in March 2000, so any prior art would have to predate that.

Interesting that the article omits these kind of details.