When Social Media Gets Political: How Message–Platform Match Affects Consumer Responses to Brand Activism Advertising

Social media has sparked a surge in online activism and sociopolitical movements. Numerous companies have also launched brand activism advertising campaigns to voice their stances on sociopolitical causes. However, it remains unclear how and why consumer reactions to brand activism ads vary across different social media platforms. To bridge this gap, we introduced a novel characteristic of social media—level of politicization—and examined how message–platform congruence in terms of level of politicization affects consumer responses to brand activism ads. In Study 1, we found that on a less politicized platform, a less politicized message (vs. a more politicized message) reduced ad intrusiveness, which in turn positively affected consumers' ad attitudes and purchase intentions toward the brand. On a more politicized platform, consumers exhibited equivalent levels of responses regardless of the message type. In Study 2, we further identified consumers' level of issue support as a boundary condition of the message–platform congruence effect, such that the congruence effect was larger when issue support was low.