Think about your consumer. A really great thing about social networking (at least I think so) is the fact that it's much more personal, more friendly. Think about the last time you made a purchase or say the last 10 times you bought something new. Did you ask someone, perhaps a friend for a reference or advice? I bet you did. It's the same online.
By becoming reputable online, you befriend your consumer. Now they see you as someone who they can come to for a reference. Do you (aka your company) sell nail guns? I don't know the first thing about nail guns, but I know that you do. So who do you think I'm going to ask?
When you participate in online conversations your company becomes more personified. Your audience sees you and the characteristics conveyed by your site. The really great thing about social networking is it allows you to get to (what seems like) a one on one level with your customer. As humans we prefer that special attention and we are more apt to act on it.