The BBC has some great pointers from SMBs looking to jump into social media.  Great quote here on the why it's so important:

Mr Bard quotes Amazon founder Jeff Bezos: "If you make customers unhappy in the physical world, they might each tell six friends. If you make customers unhappy on the internet, they each tell 6,000 friends."

And ya gotta love this one:

"Respect them. Having an audience, or customers, is a privilege, not a right - just like wearing spandex."

Full article is here:   http://www.bbc.co.uk/news/business-17549278