The document discusses applying portfolio management techniques used for loan portfolios to customer relationship management (CRM). It argues that customers can be viewed as bonds that generate cash flows for a company through repeat purchases and visits. This view of CRM as portfolio management aims to keep customers engaged over the long term to maximize their lifetime value. Key aspects of applying this approach include measuring CRM success longitudinally using metrics like repeat purchase rates, predicting customer behavior with loyalty models, and using analytics to determine the most valuable customer states to target with marketing.