  In retailing, it is important to understand customer behavior and determine
customer value. A useful tool to achieve such goals is the cluster analysis of
transaction data. Typically, a customer segmentation is based on the recency,
frequency and monetary value of shopping or the structure of purchased
products. We take a different approach and base our segmentation on the
shopping mission - a reason why a customer visits the shop. Shopping missions
include focused purchases of specific product categories and general purchases
of various sizes. In an application to a Czech drugstore chain, we show that
the proposed segmentation brings unique information about customers and should
be used alongside the traditional methods.
