This is not a comprehensive review (although you’re welcome to add more sources in comments or send me an email). This is also not a real scientific literature review. Some results are contradictory and it is up to you to judge who is right and who is wrong.
This is just a list of academic papers/theses/articles published on the topic of Couchsurfing. I used many of these papers when I was writing my thesis and articles on CS. I hope this little review will help you in your research.
This post is also available in pdf.
(Adamic, Lauterbach, Teng, & Ackerman, 2011) combines data analysis of ratings, a large-scale survey, and in-depth interviews trying to understand the ratings on CS. Many users tend to overrate other members being afraid that they may provide reciprocally negative reference or rating. Negative references are underrepresented (only 1 to 2500 positives). Authors propose rating design that would encourage more balanced feedback.
(Ayers-Greenidge, 2012) explores guest’s motivations to use CS. Author finds that motivation to be a traveller (rather than tourist) is the most important, while initial motivation to save money when travelling is also popular. Author ties trust to the concept of intimate tourism. The similarity is an important factor in selecting possible host.
(Bialski & Batorski, 2010) ties concept of trust in CS to familiarity. Using an online survey of 3000 CS members, and 30 personal interviews, authors outline three stages of the CS experience when the trust emerges: pre-selection of users, website and profile navigation and offline contact. Familiarity plays crucial role in the formation of trust.