IF you believe the polls are as close as they are AND
IF you believe it could come down to Ohio deciding the elction.
http://www.breitbart.com/Big-Government/2012/10/14/Ohio-Coal-miners-condemn-Obama
Personally though, I'm fairly confident the polls are taken in such a way that maximizes ad revenue for the media (all of it).
Without such a "close" race, (sorry for bringing 'race' into it) why would a candidate have to spend so much money advertising?