This document discusses market segmentation in the context of the single European market. It notes that segmentation may take two forms: within countries for products with significant customer differences, or pan-European segmentation for other products like airline services. Preferences may become more similar over time between consumers in different countries. Demographic characteristics can help identify potential targeted niches and describe consumer segments, as demographic data is readily available from various sources. The real test of a segmentation scheme is evaluating the results after it has been tried.