Capital One's population challenge hosted @ MindSumo. Placed in the top 5.
https://www.mindsumo.com/contests/closed-use-population-data-to-identify-promising-markets/?state=1
Wrote a blog post on this challenge, and my approach with Python/Pandas. http://randomforests.wordpress.com/2014/03/21/top-5-winner-capital-one-population-challenge-mindsumo/