Abstract — online social networking sites are the most popular sites on the internet. The second generation of web-based services is characterized by having consumer-generated content (UGC), which allows people to share information. This paper examines CGC on TripAdvisor, with a case study on the city of Lisbon. Along with a discussion on the radical changes implied by new forms of collaboration and business models, it is explored how the users collaborate to image a destination. It analyzed a sample of all the hotels On TripAdvisor.Com for the city of Lisbon, as well as forum authors and advisors’ profiles. The information available on forums and reviews is generated by users/consumers and provides relevant data for travel planning.

INTRODUCTION – Social networks are online communities of people who share common interests and activities. They provide a user with a collection of various interaction possibilities, ranging from a simple chat to multiple video conferences, and from the exchange of plain email messages to participation in blogs and discussion groups. Online social networks may also contain categorized relationships (e.g. former classmates), means to connect with friends (with self-assembled description pages), or recommendation systems for some kind of objects or activities. Popular spaces combine different functions of this type. Some of the most widely attended are systems such as MySpace (190 million users in 2007), Orkut (over 62 million), and LinkedIn (over 5.5 million).