With rapid technological innovation and ever-changing consumer preferences, smartphones have become important tool in our modern life. In the smartphone market, most users will not only consider the price and features of the phones but also the word of mouth and average sales of these smartphones. Often, customers face difficulties in their purchase process as they tried to investigate the functions and brand image of these smartphones. Therefore, in this paper, we selected nine smartphone brands and used VIKOR to rank the smartphones’ functions. Then, we used TOPSIS to evaluate the word of mouth. We also took the average sales and brand image figures for each brand into consideration. This study found that the brand image significantly affects the overall rankings of brand sales.