Many businesses are keen to use social media but hold back because of a fear of negative comments and how to manage their reputation on-line. The reality is that people will be talking about your business on social networks whether you have an official presence or not.
Customers have the right to complain and often take to Twitter as a sign of sheer frustration after their emails or phone calls have been ignored. Many large companies are improving their customer care reputation with customer service staff resolving issues in real time. Examples would be @BTCare and @Orangehelpers.
The key is to address the issue by acknowledging the complaint, apologising for the customer being unhappy and offering to investigate and find a solution. The initial contact can be made on the social network but I'd recommend taking the conversation off-line. Disgruntled customers want to explain what the issue is, they want you to listen and understand why they are unhappy, and most importantly they want a solution that they deem acceptable. If they have been frustrated with the service so far a phone call and a chat with a "real person" could turn the situation around. Meanwhile, those who have seen the exchanges on Twitter will have the impression that the business is trying it's best to offer good customer service, rather than ignoring the problem.
Social networks certainly turn up the volume on word of mouth but if you listen to your customers and approach problems in a professional manner the end result can have a positive effect on your reputation. On that note I'd like to thank Jon at @OrangeHelpers who took 5 minutes to rectify an issue I was having with broadband, fantastic customers service and very friendly too.