Reward crowdfunding is a popular channel for entrepreneurial fundraising, whereby backers receive non-monetary benefits in return for monetary contributions while accepting risks of non-delivery on campaign pitch promises. To understand contribution behavior in this context, we apply the Theory of Planned Behavior (TPB) for analyzing contribution intentionality and behavior, as well as their antecedents. We use survey data from 560 users of Finland's leading reward crowdfunding platform– Mesenaatti. Our findings show that an extended TPB model holds for reward crowdfunding and that both financial-contribution intentions and information-sharing intentions predict behavior. This highlights the dual nature of reward crowdfunding-contribution intentions and behavior, where information sharing helps reduce information asymmetry and serves as a quality signal in support of financial contribution. This paper also presents significant differences in attitudes, self-efficacy, financial contribution and information-sharing intentions between high-sum and low-sum contributors.