This article studies the way in which people get together on various meeting sites. Around the notions of trust and commitment, the author describes the resources made available by the site, which the users mobilize for mutual assessment. Examining the modes of commitment peculiar to various relational objectives, he notes how the forms and times of qualification differ from one site to another, especially in relation to the nature of the information to be obtained on the other person, who is initially a stranger. Finally, he examines the rationalization of these modes of pairing which seem to enable users to form relationships that correspond to their desires, free of the risks inevitably inherent in learning to know a stranger.