Interactive map - hover for detail
Graphic by PETER BELL
Sources: Hotline reporting
Leading the list is the Washington, D.C. market, which covers the crucial Northern Virginia suburbs and which has seen almost $50 million in total spending. Obama's campaign has already placed more than $24 million on Washington television, while Romney's campaign has bought $12.6 million in airtime there.
Voters in the Cleveland, Denver, Tampa and Orlando markets have all been inundated by between $34 million and $39 million in advertising time. Voters in the Cincinnati, Charlotte, Columbus and Las Vegas markets have all seen between $20 million and $30 million in ads.
All told, the two sides have spent almost 60 percent of their advertising budgets in the 21 markets in which the two sides have spent more than $10 million. Virginia, Ohio and Florida account for four of these mega-markets each; Nevada, North Carolina, Iowa and Colorado account for another two; and the Boston market, which covers New Hampshire, is the final mega-market.