Forrester's customer life cycle provides a framework for CMOs to reorient marketing from a linear funnel-based approach to a customer-centered approach. Making the switch to customer life-cycle marketing demands many new uncomfortable and potentially unpopular elements. These include sacrificing short-term revenue in favor of longer-term growth, investing in new resources, and innovating with unfamiliar tactics. This report will help CMOs build a business case for switching to customer life-cycle marketing. It identifies key sources of business value that come from making this switch and explains how savings elsewhere can offset investments. This is an update of a previously published report; Forrester reviews and updates it periodically for continued relevance and accuracy. We revised this edition to factor in new ideas and insights.