Another benefit of Google Alerts is that it lets you see whether Google is properly indexing your own blog posts or other Web content you're producing. If you put up a new post and don't receive a link to it in your Google Alerts email, you'll want to make sure that the search site is considering your blog--and if it isn't doing so, you should find out why.
Facebook, Twitter, and Google+ are all key avenues for branding, and users know it. When consumers want to complain about a company, many of them are more likely to tweet about it or kvetch on Facebook than they are to pick up the phone and call customer service. Although you can't control what customers say about your company, you can easily respond to the comments on each of these same services. That response, more than the complaint itself, is often what will determine how you are perceived by other customers who might come across that post or comment in their search results for years to come.
Be prompt with your responses--Facebook and Twitter won't always alert you to new posts mentioning you, so check in daily. Always post courteous and thoughtful comments tailored to the individual and the issue; don't use a canned, stock reply. "The customer is always right" has never been more true than now, especially since your conversation will be archived online, effectively forever. If you made a mistake (even a little one), apologize profusely, and present a make-good offer. You'll be surprised how often you can turn a negative comment into a positive one simply by being decent.
Reviewing the Reviews
If you sell anything to the general public, chances are good that whatever you're selling is being reviewed in some fashion. Items you sell on Amazon are reviewed and awarded a star rating. If you operate a restaurant or a retail shop, or if you perform a professional service (medicine, law, accounting), you'll collect reviews on Yelp and Google Places (among other sites), whether you want the feedback or not.