Suggest you read "The Travel Marketer’s Guide to Social Media and Social Networks"

This report was published by HSMAI
Topics covered in the report include:
* Explanations and definitions of social media and social networking
* Highlights of the way social media and social networking are used in other industries
* How travel companies are using social media and social networking in 2007
* How travel companies can use social media and social networking in the future
You can Read the Executive Summary here
Well, I didn't buy this report, but if you have feedbacks about it, leave a comment.