Responding to comments, opinion, feedback, discussion, etc. (good and bad!) is great for reputation and goodwill. This means efficient discovery through proactive monitoring is now a key aspect of social media strategy.
By way of an example - here is a video of the worldwide sports drink brand "Gatorade" and their new social media mission control centre. They have custom built technology to track and respond rapidly to mentions of Gatorade in a variety of social media.
Check out this Mashable post for more coverage of Gatorade.