This document discusses database marketing and how it has become necessary for large retail chains and banks due to their inability to know each customer individually. It covers customer databases, data warehousing, and data mining. Database marketing involves using computer technology to track customer transactions and profiles to send targeted communications instead of treating all customers the same. The document provides examples of how small merchants can develop personal relationships with customers compared to large chains. It also discusses using the RFM model and segmentation approaches to analyze customer data and identify the most profitable customer segments to target.