In the past decade, a fundamental research topic in the information systems (IS) discipline has been to examine the value of online platforms on businesses, society, and consumers, notably in the form of improved efficiency in information sharing, consumer engagement, and increased sales. However, the risks rooted in online platforms may cannibalize the value created, which have received limited attention in the literature and practice. In my dissertation, I attempt to fill this gap in the literature by providing a comprehensive analysis of the risks of online platforms from the angle of these three main entities in the ecosystem with three separate yet related essays. The first essay focuses on the risks for businesses that leverage social media platforms, and assesses how their posting on social media fan pages affects consumers’ decision to purchase and unfollow from the firms. The second essay focuses on the risks of fake news on social media and how social media platforms may use identity verification to reduce online anonymity and combat this increasingly critical social problem. The third essay focuses on estimating the risks of using monetary incentives to motivate consumers to write online product reviews, and examines how such strategy may affect product sales. Our studies have theoretical and practical implications for designing effective online platform information systems. / Business Administration/Management Information Systems