WASHINGTON (Reuters) - More than 1.1 million ads have aired in the presidential race, and President Barack Obama's campaign has invested the most money to run the most spots, an academic analysis showed on Friday.
The study by the Wesleyan Media Project showed that this year's campaign had seen more political advertising than any previous U.S. election and an increase of nearly 40 percent on 2008.
It showed that since Mitt Romney emerged as Obama's Republican challenger in early April, the Democrat's re-election campaign had sponsored about half of all the ads aired and out-advertised Romney's campaign by a 2.6-to-1 margin, both by the amount of ads and estimated money spent.
But the Republican Party and allied outside groups - unlimited-spending "Super PACs" and advocacy non-profits - have bridged the gap: The Wesleyan tally shows that overall, all pro-Obama ads outnumber pro-Romney ads by fewer than 50,000.
The study, released just days before next Tuesday's election, analyzed broadcast and national cable ads run from April 11 to October 29 based on data by ad-tracking firm Kantar Media/CMAG.
After Obama's and Romney's campaigns ($266 million and $105.4 million), the study showed that top ad spenders were pro-Romney "super" political action committee Restore Our Future ($57.6 million); Republican duo of American Crossroads Super PAC ($56.9 million) and tax-exempt Crossroads GPS ($45.9 million); tax-exempt pro-Republican group Americans for Prosperity ($35.9 million) and pro-Obama Super PAC Priorities USA Action ($32.5 million).
"This is, by far, the most advertising we've seen in a presidential election," said Erika Franklin Fowler, a co-director of the Wesleyan Media Project, which found that the number of ads aired in the 2012 race marked a 39 percent increase over 2008 and 41 percent over 2004.
(Reporting by Alina Selyukh; Editing by David Brunnstrom)