The Yahoo!'s Content Optimization and Relevance Engine (C.O.R.E.) creates 13 million story combinations a day on Yahoo!'s home page. Check out this data visualization: http://visualize.yahoo.com and explore what readers in different age and demographics groups, or with different interests or locations are reading on Yahoo.
A great interactive visualization example that show how curating existing data and presenting it in an accessible and interactive way can create extra value.
Check it out: http://beta.visualize.yahoo.com/core/