Even though there is intuitive appeal in identifying the user profile for a given service and then targeting similar nonusers, this approach can be very misleading when marketing health care services with low market penetration. If usage segmentation is employed without checking other indicators of latent demand and perceived barriers to use, significant misallocation of marketing resources is likely to occur. Confidentiality and embarrassment can be significant barriers to use by segments that are excellent patient prospects. In this study of mental and behavioral care, females and non-whites were found to be more concerned with confidentiality than were members of the user group. Lack of awareness can be a much bigger impediment to adoption than negative attitudes. Health care marketers need to design communications that not only increase awareness and familiarity for services with low market penetration, but also address other issues of concern to highly receptive segments.