Abstract
The birth of Web 2.0 tools has created a new paradigm for word-of-mouth communication. Bearing in mind the relevance of tourists as agents in destination image-formation processes, this research discusses the new role they play in this paradigm, and how it affects and modifies the seminal typology of image-formation agents originally proposed by Gartner [1994. Image formation process. Journal of Travel and Tourism Marketing, 2(2), 191–216. doi: 10.1300/J073v02n02_12]. The results focus on the effects of Web 2.0 tools on the credibility, market penetration and costs for the destination of tourists' actions as image-formation agents. Implications for destination marketing organisations are also considered and discussed.