Purpose: The purpose of this paper is to examine how social topic information (STI) and corporate social responsibility commitment (CSRC) substantiate the firm's CSR claims and promote message persuasion. Design/methodology/approach: A 2×2 between-subjects experimental design was used to examine the impact of STI and CSRC on output variables using an online sample of 176 participants in Australia. Findings: The study found that manipulation of STI had a statistically significant impact on outcome variables, but that CSRC did not. Research limitations/implications: The study was limited to Australia and used a fictitious brand in the experiment. Practical implications: For marketing communications and brand managers, this study informs CSR-based corporate image advertising. Social implications: Support for more socially responsible businesses through responsible consumption can potentially transform product attributes and markets. More effective CSR communication is critical to this response. Originality/value: To date, no research has examined how consumer persuasion of CSR advertising claims might be enhanced using message variables. This study has implications for theory and practice for the effective communication of pro-social achievements, and suggests further research areas. © Emerald Group Publishing Limited.