In March/April, 2014, we proposed to migrant adults with low levels of education in a post-literacy programme at the Cours municipaux pour adultes de la Ville de Paris (adult training provider of the City of Paris) to post messages on discussion forums and in the comments section of a newspaper online. While favoring the digital inclusion, the objective of this teaching strategy was to lean on the keen interest tools and digital features arouse in this type of audience to generate an effect of training in the readingwriting tasks. These tasks gave rise to intercultural meetings on sites of social Web perceived by the learners as social spaces of exchanges and mutual aid. Our experiment questions the links of synergy between traditional and digital literacies and the potential of social Web as mediator, or even as a lever in a process of learning.