This paper is based on the idea that user generated contents (UGC) about holidays, travels and destinations, widely propagated throughout modern social networks, have a topical relevance respect to the diffusion of the image of tourist destinations. More than other information transmission mechanisms, word of mouth (WOM) strongly influences consumer behavior and decision-making, especially when ‘experience goods’ (as in the case of tourism) difficult to be evaluated before their consumption are concerned (Wilson 1994; Griffin 1995; Silverman 1997; Rosen 2002; Dall’Ara, 2002; Lambin, 2004). The advances of ICT tools and the emergence of the Internet strongly influence word of mouth, since larger and larger WOM networks are being settled where travelers’ and tourist services contents are simultaneously diffused. In the paper the features of the so-called electronic word of mouth (e-WOM) will be discussed in terms of the web transmission of the free users generated contents (UGC).