An important challenge in Web-based health promotion is to increase the reach of the target audience by taking the target groups' desires into consideration. Data from 505 members of a Dutch Internet panel (representative for Dutch Internet users) were used to asses the target group's interests and needs. 28% participated in Web-based tailored lifestyle programs, 57% expressed an interest in such programs, and 15% expressed no interest. Interest in Web-based programs was predominantly caused by a general interest in lifestyle and online tests. Participation in Web-based tailored lifestyle programs should not take more than 17 minutes per occasion. 84% were interested in follow-up testing after the initial participation. Responders were particularly interested in physical activity and nutrition. Hardly anyone was willing to pay for participation. The results from this study support the use of Web-based tailored lifestyle programs in behavior change efforts.