Facebook Likes - a lot of "interest" data being collected

Facebook likes are becoming commonplace - not only in facebook pages but off-network (outside of facebook.com) as well. Blogs use it, brands are incorporating it. Just check out the use of facebook "likes" in websites.

So, the question arises - how can we use this data more efficiently? I've always believed that, apart from being the place that folks are spending most time on the internet, facebook is a very rich data store. Facebook knows what its audience is doing both on and off-network. And that's a rich source of data. Think of its benefits:

1. Tracking trends. Urban outfitter knows not only the number of customers who "like" their product but their specifics as well (demo and profile)
2. I should rephrase, its not Urban outfitters but Facebook. They can sell this data back to the client!
3. Word of mouth marketing. There is no better way to sell than word of mouth from your own friend. 80%+ sales are from word of mouth marketing. Sharing feature of like is best suited for it.
4. Virality. Sharing with friends.