Wealthy Super PACs can raise unlimited funds from corporations, unions, individuals and groups to support or oppose candidates, initiatives, or legislation. They don't have to report their donations immediately, but they do have to report most of their spending within 24 or 48 hours. How have the Super PACs been spending their money? We worked with Visual.ly to take a look at the trends.

We were struck by how much money Super PACs spend on advertising and voter contact (click the pies to see the breakout by medium).

What do you notice?