The internet has caused a revolutionary change in communication. Being a highly information-based form of business, the tourism industry has been particularly affected by this development. Opinions on the web submitted by customers are of considerable relevance for reducing uncertainty before purchasing a tourism product. The reputation of a travel company is a major piece of information to customers. This reputation is created within the dialogue among customers. This work focuses on the relationship between travel company reputation and travel decision, using approaches from New Institutional Economics and Behavioural Science. On this basis, a theory-based model will be developed and analysed.