Customer Service Insight.
Tonight, amongst other nonsense, I heard a creative director declare that twitter could be a great customer service tool. No it can't. It can be a great customer mood monitor, it can be a great way to field customer complaints, but that's not what we should understand as customer service.
Customer service is what happens throughout your contact with the customer. If you do it right, you shouldn't need to have a Twitter presence because your customers will be happy.