Our research examines the manner in which Web users choose between participation in the Internet economy and protection of their personal data. We study the influence of various contextual elements (e.g. the privacy policies posted on sites) and individual characteristics (e.g. privacy concern) on willingness to communicate personal data online. An experimental study carried out on a sample of French students provides the framework for testing a conceptual model. The impact of privacy concern on Web users' attitude is confirmed. Privacy policies and the amount of data requested are also shown to influence willingness to self-disclose. Finally, our findings establish that situational factors have a greater impact on the decision to provide personal data than personal convictions.