Online product reviews are important information sources in consumer decision-making process. According to 2010 Pew Research Internet Project, eighty five percent of Americans have searched for online reviews about the products and services they buy. Despite the importance of online product reviews in product evaluation, relatively little attention has been given to investigate the influencing factors of consumer trust towards online product reviews. There is an emerging need to address the role of source characteristics and content attributes in enhancing the credibility of online reviews. The current research examines how perceived similarity between reviewers and consumers, source prestige, and argument quality influence the review credibility and consumer trust in product reviews. The results from Experiment 1 indicate that hotel reviews produced by a high prestige source induce more trust than those produced by a low prestige source under the low similarity condition while a reversed relation is found under the high similarity condition. The findings from Experiment 2 and 3 suggest that reviews with strong argument quality lead to more consumer trust and higher source credibility than reviews with weak argument quality. These results indicate that regardless of whether the similarity between the source and the recipient is high or low, argument quality and source prestige influence the effectiveness of online product reviews. Argument quality and source prestige contribute unequally to consumer trust depending on the product categories. Though the hypothesized effects of the perceived similarity on consumer trust are not supported in Experiment 2 and 3, the results from these experiments reveal that perceived similarity may not be the only influencing factor for source trustworthiness. Furthermore, the results suggest that source prestige serves as a critical indicator for source trustworthiness while argument quality connects both trustworthiness and source expertise.