We thank our anonymous reviewers and our shepherd, Jennifer Rexford, for their invaluable feedback which helped substantially in improving the quality of the paper. We owe our gratitude to Dave Andersen, Tom Anderson, Jon Crowcroft and Scott Shenker for their detailed technical feedback at various stages of this work. We thank Nick Feamster and Matthew Caesar for providing us with MPEG, PESQ processing scripts and several students at UC Berkeley who read earlier drafts of this paper and provided invaluable feedback.