When we saw Noam Cohen's January 2011 New York Times article about Wikipedia's large gender gap, we wondered what light we could shed on the questions and observations raised by Mr. Cohen and the results of the Wikimedia Foundation's 2009 survey. Drawing upon the experience and the data sets that we've accumulated while researching Wikipedia and other online communities for the past decade, we explored Wikipedia's gender imbalance and wrote a paper about our findings. We've recently heard that our paper has been accepted for presentation at WikiSym 2011.
Amazon reviews and tags don't always get used "seriously" -- the Kevin Federline album Dan linked to is a great example. It's been somewhat of a Amazon tradition to target certain products with irreverent and funny reviews. Sometimes, they're removed by Amazon since they're pretty inappropriate, but others, such as reviews for David Hasselhoff's album, whole milk, or recreational tanks (...interesting cross-sells!) have been left alone.
Now, the point of writing these reviews is probably not to shill for the products and make more sales, but their existence has undoubtedly driven disproportionate amounts of traffic to the product pages since people find them funny and send the links to their friends. How does phenomena like this fit in with recommender system security? Is Amazon benefiting from it?