A couple of weeks ago I purchased a couple of books from Barnes and Noble in Tysons Corner: Sex, Drugs, and Cocoa Puffs from Chuck Klosterman, and The Omnivore’s Dilemma from Michael Pollan.

I certainly thought it was a little interesting later that week when I logged onto Amazon and was presented with:

According to Amazon, The Omnivore’s Dilemna was recommended to me because I purchased Guns, Germs, and Steel as well as The Long Tail (at the time of writing, the Klosterman book was no longer available).

Now I am certainly familiar with Amazon’s practice of matching recommendations based on activity while on-site but it seems really eerie that the two books I just purchased from Barnes & Noble were literally the top two recommendations when I logged into Amazon.com.

There are basically three possible explanations for this:

1. I am pathetically predictable;
2. Amazon had someone follow me into the store and observe the books I purchased;
3. Amazon somehow either shares or purchases data from Barnes & Noble…

From a competitive standpoint I can’t quite comprehend why Amazon and Barnes & Noble would possibly share data, or why Barnes & Noble would sell customer data to Amazon. Also, if they had accurate data, they wouldn’t offer me a book I had just purchased.

I still don’t know how else to explain why the authors who had written books I purchased at Barnes & Noble would show up as recommendations when I log-in to Amazon.

Anyone have any ideas?