This study focuses on the effect of Corporate Social Responsibility (CSR) initiatives on financial performance, using the information disclosed by companies on their websites. The final sample is made up of the 122 companies listed on the Madrid Stock Exchange (Spain). The empirical analysis entailed two phases: an analysis of the differences among the companies' Financial Performance (FP) depending on their CSR strategy, and the use of a hierarchical cluster analysis and a multiple linear regression in order to explain the effect of CSR practices on corporate performance. The results of the analyses were significant and in the direction hypothesised. That is, CSR improves financial performance and, when considering the intangible components of CSR, the relationship is stronger for the company's long-term performance than for its short-term performance.