So why do social media? 
That's where the people are.  If you would like to be seen and heard, and if you would like to “see your customer real,” and if you would like for your customer to see you real, then Social Media is a solid opportunity.

“Out of the overflow of the heart, the mouth speaks.” 
If you engage in social media with a too-naked intention of monetizing your activities, you will be sensed for the fraud you are.

“Seeing your customers real”
means moving past efforts to categorize, capitalize, and manipulate them.  You must enter into a subjective relationship with them and become positively-biased in their favor. This means giving of yourself and your time and your knowledge.  All of which is one reason why successful, social media strategies are huge Time Sucks.

“Giving of yourself”
means sacrificing something real to signal your intent (a la Tom Wanek's signaling theory).  If your employees are using social media on your behalf, you'd better empower them to spend some kind of money as the need arises, and using their best judgment.  EXAMPLE: The other night, a Zappos Customer Service agent heard our baby crying in the background and – instead of accepting a return on our daughter's defective sneaker – simply sent us a new one via next-day air.  No extra charge.  Wife put it up on FaceBook immediately. 

People like to do business
with those who they've come to see as real human beings, just like them.  Even more so, they like to do business with people they feel are positively-biased in their favor.  Even though social media isn't easy to monetize or to track ROI from, there are real business benefits.

– Jeff Sexton (again)