Sister72 (flickr 2007)
Amount spent on radio advertising in the U.S. in 2006:

$21.7 billion

Source: Wall Street Journal, 7/3/2008

 
   
  Total compensation paid to Rush Limbaugh in a contract signed in July 2008:

$404 million
On July 2, 2008, Rush Limbaugh signed an eight-year contract with Clear Channel Communications for $38 million per year, plus a $100 million signing bonus.
Source: Wall Street Journal, 7/3/2008

 
   
  Total compensation paid to Rush Limbaugh in a contract signed in July 2001:

$285 million
On July 18, 2001, Rush Limbaugh signed an eight-year radio contract with Clear Channel Communications paying him $285 million, or around $35 million per year.
Source: Palm Beach Post, 7/20/2001

 
   
  Amount spent on radio advertising in the U.S. in 2007:

$21.3 billion

Source: Wall Street Journal, 7/3/2008