In this paper, we discuss an approach to "design for wow" that focuses on the emotions that constitute a wow-experience. In this approach, the eliciting conditions of these emotions are used to define a product character with a high wow-impact. In addition to the approach, a measurable wow-index is introduced. First, a concept of wow is described in which wow is explained as a combination of fascination, pleasant surprise, and desire. The eliciting conditions of these three emotions are examined and combined to a "wow-appraisal." This concept is applied in the design of a mobile telephone. A combination of qualitative and quantitative research methods was used to formulate concern themes relevant for the wow-appraisal. These themes were used to create a layered product character and a prototype of the final design. An evaluation study demonstrated that the product designed with this approach rated higher on the wow-index than alternative products.