Campaign advertising is still the number one way to reach mass population. But it's expensive and only the well financed campaigns are able to compete. No candidate has been able to keep up with Barack Obama, who was able to invest in a 30 second advertisement during the Super Bowl. The most expensive campaign advertisement ever.

Joining us today to talk about this is Josh Israel, Senior Researcher for The Buying of the President project with the Center for Public Integrity.

"Numbers seem to indicate .. that the Obama campaign has spent more than 31 million dollars on campaign commercials, and the Clinton campaign just behind that with almost 25 million dollars in TV ads... Certainly, its a very profitable business to be selling advertisements to political candidates. If you want to be on at prime time, they are going to charge you as much as they can. And, unfortunately for the candidates, they can charge a lot."

The Barack Obama Super Bowl ad: