A key property of the World Wide Web is the possibility for firms to place virtually costless links to third-party content as a substitute or complement to their own content. This ability to hyperlink has enabled new types of players, such as search engines and content aggregators, to...

An important current trend in advertising is the replacement of traditional pay-per-exposure (pay-per-impression) pricing models with performance-based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action (PPA) mechanisms are becoming the predominant...

Online Reputation Systems are a key, but under-appreciated, component of virtually every social web application. They play an important role in inducing user participation, good behavior and quality contributions. Despite their importance, however, their practical design and implementation has,...

This paper studies settings where a number of sellers of different reputations for honesty simultaneously offer sealed-bid, second-price, single-unit auctions for imperfect substitute goods to unit-demand buyers. Among other applications, these settings can serve as an abstraction of large scale...

An important current trend in advertising is the replacement of traditional pay-per-exposure (aka pay-per-impression) pricing models with performance based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action mechanisms are becoming the predominant...

Several properties of online interaction are challenging the accumulated wisdom of trading communities on how to produce and manage trust. Online reputation reporting systems have emerged as a promising trust management mechanism in such settings. The objective of this paper is to contribute to...

Social media have great potential to support diverse information sharing, but there is widespread concern that platforms like Twitter do not result in communication between those who hold contradictory viewpoints. Because users can choose whom to follow, prior research suggests that social media...

Online "feedback mechanisms" - also known as "reputation systems" - have been implemented in the most important private e-markets, such as eBay, Yahoo!, Amazon to foster trust and cooperation among trading partners. In this paper we discuss the main issues relevant for the optimal design of such...

Massive Open Online Courses (MOOCs) have faced a number of challenges developing sustainable revenue. In response, this article describes possible business models based on who pays (states, students, employers, or sponsors) and what they might pay to receive (content, skills certification,...