The original use of association rule algorithms was for market basket analysis, such as the grocery store example we've been using throughout this chapter. This is a clear-cut application for association rule mining. Market basket analysis can be used both in physical stores and in e-commerce stores, and different models can be maintained for different days of the week, seasons, or even for specific rare events, such as an upcoming concert or a hurricane.
In fact, in 2004, The New York Times (and others) reported that Walmart used association rule mining to figure out how to stock stores in advance of hurricanes. Walmart discovered that the association with the highest lift right before a hurricane wasn't bottled ...
