Aisling, you raise a good point. I agree that people who are not commenting may be listening. A Brand's strategy should keep this in mind and tailor messaging to this specific audience. The challenge is to get listeners to buy and then spread the word. I suppose that even if you can get a listener to buy, that too is a win. Sometimes though, brands have to determine where to spend their money. Often times it is not on the listener, but on the influencer.