In primates and humans alike, the number of social relationships an individual can have is constrained in part by its social cognitive competences and in part by the time available to invest in face-to-face interaction. I will show that time, in particular, has a significant effect on the quality and stability of social relationships. If the quality of a relationship is a function of the time invested in it, then we might expect a technology that allows an individual to cut through the time constraints inherent in face-to-face interaction will allow larger social networks to be maintained. Social networking media on the Internet provide one obvious possibility in this respect. I will review evidence suggesting that the Internet does not (and cannot) help us to widen our social horizons, and will show why. Presented by Robin Dunbar (Anthropology, University of Oxford, UK). Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/