Here are a couple of quick examples of companies using Twitter for customer service, business-to-consumer marketing, business-to-business marketing, and public relations:

Customer Service – The massively popular online shoe store, Zappos.com, takes customer service to an all new level of buying utilizing Twitter as a line of communication with its customers.

Business to Consumer Marketing – The Ford Motor Company is posting in 140 characters or less to promote their new Fiesta model. You can learn more about it at www.fiestamovement.com.

Business to Business Marketing – Duct Tape Marketing started a few years ago with their book and website that catered to helping small businesses get more customers. Now, they use Twitter as part of their marketing tool belt to reach out to businesses that need their services.

Public Relations – The company that sets the standard in womens’ and mens’ accessories, Louis Vuitton,  uses Twitter to reach out to bloggers in the Paris fashion industry.

These are just a few examples of using Twitter for business. Be sure to take a look online for more examples of how you can use Twitter for your business.