While you're filling out your expertly analyzed bracket, you might want to take a look at how March Madness fandom is spread across the country with this map from Facebook (via Gizmodo). Michael Bailey of Facebook's Data Science team analyzed the way "likes" are spread through teams and conferences, across the country—in similar fashion to this Super Bowl map.
Here, for instance, Facebook looks at the conference divide. Bailey points out in his analysis how the ACC fan base is spread across the country, despite pockets of dominance for other conferences.
Facebook then divides up data by regions, No. 1 seeds, Cinderellas, and rivalries—see, for instance, how North Carolina seems to conquer more of the country than Duke:
That said, Duke's dominant, looking at all the teams in the midwest region:
Just as UNC does in the South: