The world of US political adverts explained in 60 seconds

The 2014 mid-term election in the US is projected to break records in the money spent by candidates and political groups.

A large portion of the money will go to adverts which reach the eyes and ears of 80% of Americans.

But how effective are these political adverts and just how much do they cost?

Data compiled by the Pew Research Center presents a clear picture of the political battles over the airwaves.

Produced by the BBC's David Botti