NEW YORK (October 18, 2012)--Independent groups supporting Mitt Romney have helped the GOP challenger match or even exceed President Barack Obama's TV ad spending in dozens of media markets in battleground states, but Mr. Obama is still getting more value for his money with his ads.

Under federal law, stations must offer presidential campaigns a discounted price to run their spots in the two months leading up to Election Day, which in some cases means that Mr. Obama pays almost half as much for an ad.

An Associated Press analysis of presidential campaign advertising data since April found that pro-Romney spending has exceeded pro-Obama ad spending by at least $65 million across the eight states expected to decide the election, Colorado, Florida, Nevada, New Hampshire, North Carolina, Ohio, Virginia, Iowa and Wisconsin.