• Some companies view interaction on social networks as a hassle that requires time and money, but customers have come to expect it.
• A customer cares about two things: How quickly a company responds to them, and the quality of that reply.
• Maritz Research conducted a study that showed 85 percent of customers "had a favorable impression toward receiving the response through social media," which differed from other customer support channels like phone and e-mail.

From the article:

Consumers expect companies to interact with them on social networks. Some companies see this as a hassle because they have to invest more resources to support their social media accounts, while others see it as a competitive advantage. Big-name companies like Zappos and Comcast have defined their customer services using Twitter. GoDaddy.com even uses the service to respond to customer complaints and questions.