Boerman, S.C., & Van Reijmersdal, E. A. (2016). Informing consumers about hidden advertising. A literature review of the effects of disclosing sponsored content. In P. de Pelsmacker (Ed.), Advertising in new formats and media: Current research and implications for marketers (pp. 115-146). London, UK: Emerald Group Publishing.

Abstract:
Purpose: This chapters provides an overview of what is currently known in the scientific literature about the effects of disclosures of sponsored content on consumers’ responses.
Methodology: We provide a qualitative literature review of 21 empirical studies.
Findings: Awareness of disclosures is rather low, but when consumers are aware of a disclosure, it successfully activates persuasion knowledge and can increase brand memory. The literature shows inconclusive findings with respect to the effects of disclosures on attention paid to sponsored content, critical processing, brand attitudes, and purchase intentions. In addition, the literature shows that modality of the disclosure has no significant effects, but the content of the disclosure, its timing, its duration, receivers’ moods, and their perceptions of the sponsored content or the endorser are important moderators.
Research implications: More research is needed on differences in effects of disclosures in different media and on disclosures of online sponsored content online (e.g. sponsored tweets and vlogs).
Practical implications: This chapter provides advertisers with insights on how disclosures affect the persuasiveness of sponsored content in several media.
Social implications: For legislators, explicit guidelines on how to create effective disclosures of sponsored content are provided. For example, to increase persuasion knowledge, disclosures should be portrayed for at least three seconds and if logos are used, they should be accompanied by texts explaining the logo.
Value of the paper: This overview is a valuable starting point for future academic research in the domain of disclosure effects and provides insights for advertisers and legislators.

Keywords: disclosures, forewarnings, sponsored content, brand placement, embedded advertising, persuasion knowledge

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