The following website from the University of Oregon's 'Teaching Effectiveness Program' includes a discussion of the benefits of using student feedback to improve a course:

"Student feedback is an invaluable component in the wide array of tools that can be used to improve teaching. By gathering midterm feedback, courses can be adjusted mid-stream to make them better learning experiences for students. Through careful consideration of end of the term feedback, courses can be improved each year. Asking for student feedback connects students and instructors and creates a sense of good will."

from www.uoregon.edu/~tep/resources/assessment/usingfeedback.html