Second, it allows you to be a an expert in your business area. You can create content that is aimed at providing up to date and relevant information for readers about what is going on in your field. This content can be words, video or both. If you create great content, people will come to your site to see it. Readers will 'Like', 'Share', 'Tweet', '+1'and more. By doing this, you are boosting your online profile and extending your social reach to more people, which is exactly what you want to take place.
Finally is the use for customer service and customer satisfaction. More often now if a customer has had a great experience with your company or equally a terrible experience, they will take to Facebook or Twitter to tell the world about it. Whether your company is on Social Media or not it is happening. People are talking about you, and you need to be there to respond to them.

If a customer complains publicly through a Social platform like Twitter or Facebook and then within minutes they have a response from you saying something simple such as "We are sorry you have had a negative experience. Please contact us with more information so we can help you to get this matter resolved" the customer feels valued because they know you took the time to respond to them and they know you are genuinely concerned and wanting to help. Your best customers can be the ones who had a bad experience but you turned it around. To monitor what people are saying about you, your staff or your company, use http://www.google.com/alerts to receive updates in your inbox about what people are saying. Set up alerts for your company name and top company personnel. Make sure to use "quotes" around more than one word (Ex. "Xstreme Media") to insure you only get alerts about the entire phrase. So, go forth and be social. You will be glad you did.  Watch for 4 more uses coming soon.