The present study (1) develops a dynamic, individual hierarchical model of the importance of vacations to Quality of Life (QOL), and (2) introduces this concept as a novel segmentation base, acknowledging that not all people want to go on vacation. The proposed Grevillea Model of the Importance of Vacations for Quality of Life is tested empirically by examining 1000 survey responses. Results show that 10% of Australians perceive vacations as critical to QOL. Another 60% perceive vacations add to, but they are not essential to QOL. Practical tourism marketing implications include: (1) vacations are not important to all people; therefore, mass marketing is a waste of resources, (2) people viewing vacations as essential to QOL represent a highly attractive market segment because they are likely to be crisis-resistant, and (3) a vacation's importance to QOL changes over life-stages.