The goal of product design is to obtain the maximum effect with minimum cost in functionality and aesthetic beauty. Consumers are attracted to the designs that reflect their use behaviors and psychological responses more than they are to the simple visual representations. When product functions and qualities are similar across products, customers make their purchasing decision upon aesthetic form. Form presents a significant competitive factor that improves the value of a product. Overall, the purpose of this study is to examine the most important product design factors that affect the market share trends of mobile phone companies. Study uses product characteristics for 1,028 mobile phones released between 2003 and 2008 as a case study. Multiple linear regression analysis is used to select highly correlated variables that influence the market share, and Mallow's Cp method is used to determine the best-fitting model. The Partial Regression Coefficients are used to evaluate the relative importance of design criteria. The nine mobile phone design features that affect the market share were identified, and the block form style is determined as the most important design factor. Using these approaches, this study demonstrates how investments should be directed in the next mobile phone design process.