Funny you should ask--CS Review is a complimentary service for its first year of use. You are automatically registered for the service if you already own CS5. CS Review is a great asset in the creative review process. It helps to reduce back and forth emails, by allowing clients or collaborators to give location specific comments and feedback to a project that is shared by an author. You can even act on this feedback, and implement changes with other Creative Suite programs such as Photoshop, InDesign, and Illustrator. Let me know if you have any other questions.