This study investigates system generated cues (SGCs) that influence microblog users’ reposting behavior from the perspective of source credibility. A comprehensive set of SGCs were identified through an exploratory qualitative study (study 1) to reflect each source credibility dimensions (ie. expertise, trustworthiness, attraction and coorientation), and were later adopted in a quantitative study (study 2) to test robust nature of the conceptual framework of source credibility and its impact on users’ actual repost behavior when incentives are presented to them. Data indicate that by holding expected reward and perceived cost constant, all dimensions of source credibility were found to have significant main effects on repost behavior, with no interaction. Number of friends to @ was found to be inversely related to repost behavior. Implications of these findings are discussed, along with limitations of the current study and directions for future research.