This article investigates how the type of contents in content curation sites affects the effectiveness of branded contents as a digital advertising tool. Underlying the widespread views of the effectiveness of a content curation site is the assumption that building relationships with other like-minded consumers who share common interest in the product or brand will be influential in forming bonds of the consumers to the brand as well. The study argues that such effectiveness of branded contents is influenced by consumers’ perceived credibility of the contents. The present study used attribution theory and source credibility theory to explain how consumers interpret the motive of companies or brands using curation commerce sites.173 undergraduate students who enrolled at a Midwestern university participated in the online experiment. The findings of a 2 x 2 x 2 mixed factorial experiment indicate that a significant three-way interaction effect of sponsored result, product knowledge, and product involvement on expertise The implications of the study are discussed with regard to the design of marketing contents in content curation sites.