One of the funniest internet fads has to be the popularity of the Three Wolf Moon t-shirt on Amazon. Spurred on by a single sarcastic review in November 2008, a herd of digital citizens quickly formed to buy and subsequently mock the garment, which is shown below:

The way the herd buying behaviour works for the shirt conforms closely to the information cascades theory of Bikhchandani et al (1992): a person receives a signal about the apparent merits of the 'buy' decision (reads the Amazon reviews), then decides to buy and announces this in public (i.e. writes his own review). Others follow.

It seems that producers of mock-worthy goods have a special edge in trying to start a internet sales herd: buyers have an incentive to share their purchase decision (something the information cascades theory takes for granted). Shirt owners do not only get to share laughs with their friends, they also get to share laughs with like-minded individuals on the web by posting a funny review. Buying the shirt is only half of the 'product experience' - or as one reviewer puts it:

When I first saw this review I thought, "Why would anyone want to write three longish paragraphs about a wolf shirt??!?" But then I read it.

Now, if you'll excuse me - I have some web shopping to do.