Trouble with recommenders ..
Anyone who shops at Amazon is familiar with the "People who bought XXX also bought YYY"" recommendations that dominate the front page. These recommendations must work because Amazon and other online stores rely on them heavily. However, there are problems with these automated recommenders such as unfortunate pairings made recently by Walmart. For one thing, Amazon doesn't seem to notice that kids grow up. Five years ago, for example, I bought some books in a series for my 9 year-old daughter. Now five years later, I still get recommendations for books in the same series even though my daughter is 14 years old and wouldn't be caught dead reading a book from that series (at least she wouldn't be caught dead being seen reading one).
Rebecca points me to an article in yesterday's New York Times called "Like This? You'll hate that. (Not all web recommendations are welcome)" that describes some of the problems with today's recommenders. An interesting read.