Increasing numbers of internet platforms lean on the geographical proximity of internet users in order to organise co?present meetings. This paper links together two studies based on participant observations and interviews: The first one concerning “OnVaSortir” [“We are going out”], a platform for recreational encounters between inhabitants of the same city, and the other one on “BlaBlaCar,” a well?known website for car-sharing. Beyond the diversity of what they offer, these two platforms enable their members to multiply encounters with unknown people. This paper analyses such meetings in the view of sociological works on sociability and interpersonal dynamics. It introduces the notion of relational experiences to define ephemeral meetings that are hidden from network members’ sight and that extract themselves from lasting relationships despite their personal dimension. Conversations with strangers who meet in a rather heterogeneous social context offer potential for rich exchanges. Such exchanges are influenced by the individuality of the participants, and their intimacy is even more surprising given the utilitarian dimension of the meeting. The relational experience among strangers is also characterised by collective discipline and adjustment in order to realize the shared activity previously chosen on the platform (journey, visit...). Therefore, this sociability hybridises a culture of cooperation among internet users with more standard relational frameworks, including merchant exchanges and friendships.