New communication challenges for companies that use social media are: 1) the knowledge and control of the degree of alignment between communicated and perceived brand personality in order to measure the effectiveness of competitive positioning, and 2) the measurement of engagement among consumers who share comments about brands in online communities. Our research proposes research tools that can help fashion companies meet these challenges. In particular, we present an innovative methodological approach that combines netnography and text-mining to extract and analyze data from online communities of fashion brands.