The unintended consequences of disclosure: effect of manipulating sponsor identification on the perceived credibility and effectiveness of smoking cessation advertisements.

One reason that tobacco-sponsored smoking cessation ads are less effective than those sponsored by public health agencies may be that the persuasive arguments in tobacco-sponsored ads are inherently weaker than arguments made in public health ads. An alternate explanation is that sponsorship disclosure on the face of the ad activates resistance, partly because of credibility judgments directed toward tobacco companies. The authors test hypotheses in a 3 (sponsor identification) × 2 (ad content) randomized factorial experiment (N = 270). Results indicate that judgments of sponsor credibility play a mediating role in perceptions of ad effectiveness, with identification of a tobacco company as the sponsor of cessation ads undermining perceived credibility compared with the same ads without the tobacco company identified. However, the reduction in credibility resulting from tobacco sponsorship can be partially overcome when the sponsor is placed on more direct ad content (public health ads). The effects of credibility on perceived effectiveness were stronger for more ambiguous ad content and driven by participants with lower levels of involvement (nonsmokers). Credibility judgments are not as important when the ad content is more direct about the health consequences of smoking. Implications of study results for theory and public policy are explored.