The evolution of Twitter as a business tool is gaining momentum. Within the past year Twitter has outgrown its initial consumer-based objective to become a business phenomenon. Companies, in particular PR and marketing folks, share links, interact with customers and prospects, and monitor competitors on the microblogging site. And now, the customer service departments are starting to take advantage of the real-time interaction potential with customers.

Three companies – Zappos.com, Southwest Airlines, and Staples – share their approach to Twitter as a valuable customer service channel.

ZAPPOS.COM -- @Zappos_Service