No changes were made in the Abstract. Please use the previous Abstract that was submitted

In many industries, Internet referral services, hosted either by independent third-party infomediaries or by manufacturers, serve as digitally enabled lead-generators in electronic markets, directing consumer traffic to downstream retailers in a distribution network. This reshapes the extended...

We develop a model of vertical differentiation in the Internet search engine market. A key property of the model is that users who try out one engine may be dissatisfied with the results, and consult another engine in the same session. This residual demand allows lower quality engines to survive...

The increasing availability of individual-level data has raised the standards for measurability and accountability in digital advertising. Using a massive individual-level data set, our paper captures the effectiveness of display advertising across a wide range of consumer behaviors. Two unique...

Online platforms offer access to a larger social group than is generally available through offline contacts, making the internet an emerging venue for seeking casual sex partners. The ease of seeking sex partners through classified ad sites may promote risky behaviors that increase transmission...