Can brands respond to all customers in social media?

It really is an interesting problem that faces many of the larger brands. Can they possibly respond to every customer complaint/inquiry that happens in social media? The answer is probably no. However, it's probably a slippery slope to look like you are playing favorites by only responding to the "social media elite." That's why I liked this post from Jason Falls. He recaps two incidents he's had recently that both received resolution, while two of his friends were not nearly as lucky. Jason has about 7,000 Twitter followers. Curious...are we paying so much attention to influencers in our own analyses for clients that we are losing sight of what social media is really about--listening and engaging?