It's not only brands that can benefit from paying attention to the buzz surrounding media concerning them on social networks - it's the ISPs that this media flows across too.
For example, with the knowledge of what online videos influencers are watching, an ISP could make the educated guess that these videos will attract more viewers and conversations in the future, as knowledge of the videos existence and value makes its way through local members of the influencers social networks. Then they could preferentially cache the data earlier and for longer. This way their networks could accrue a reputation for being 'faster' (at least for the most popular media) than their competitors and potentially cut down on the amount of international bandwidth they need.
This doesn't have to be done in a way that abuses the trust that customers put in their ISP to take reasonable steps to protect their privacy online, i.e. Hoovering up everything a particular customer looks at. In fact, if they were to get the information solely from the influencer's freely shared data in social networks, they could gain a greater benefit as it doesn't matter whether the influencer is a customer of their network or not.
In social media terms, this is the only data that matters. As we "Find, Filter and Forward" in Mark Pesce's words, we make precisely the judgement that the ISP can benefit from - that this thing is worth looking at, and thus worth caching. The smart pipe knows what you want to watch before you even know it exists.
I wonder if Google is already doing this with the social network data they get through FriendConnect from interactions on networks like Twitter - fine tuning the performance of their Youtube caches around the world.