I'm assuming you have a targeted buyer persona and are following up in the below article You do have a buyer persona, right? If not, read that article first, then come back here.
Using social media to promote your brand is a powerful tool, but with that power comes responsibility. Do it poorly, and it will hurt your business.
Do you ever have a friend that loves a specific brand, to the point that they evangelize and only sing their praises? How do these brands build such loyal cohorts of customers?