The staggering amount of money being spent on television advertising this campaign season continues to amaze. With the controversial Citizens United Supreme Court ruling opening the door to almost unlimited campaign season spending, the two major parties have been joined by a host of super PACs (especially anti-Obama ones) feverishly buying up ad time in swing states in hopes of winning over key voters.

The sheer volume is hard to comprehend. This year, more than 97,000 political ads have aired in the state of Iowa alone; nearly 115,000 have been broadcast in Ohio. That's two and a half times the number that aired in Ohio four years ago.

Local viewers might be numb from the onslaught, but the barrage translates into blockbuster business for local TV stations. In Iowa, they've banked nearly $30 million during the recent political ad blitz; a blitz that shows no signs of abating. And while stations by law must sell airtime to candidates at the lowest possible price, super PACs and other outside groups must pay the going ad rate. And with so many groups trying to squeeze onto local stations, the ad rates in swing states are up, which means even more profits for key station owner groups, such as Belo Corp., E.W. Scripps, Gannett and Sinclair Broadcast Group.

In fact, while national TV advertising for the second quarter grew by less than two percent this year, the local television advertising business exploded, jumping nearly 10 percent. “Astronomical” campaign spending from the first-ever Citizens United election season fueled the rapid growth. (Campaigns rarely run television ads on a national basis, instead preferring to target voters in specific states and markets via local stations.)

The sudden eruption of local TV advertising money, as well as the wealthy forces behind the surge, represents one of the most important stories of this campaign season. How have local TV stations done in terms of covering that essential story?

Very, very poorly.

A new study from the media reform group Free Press suggests that in key swing state television markets, stations on the receiving end of multi-million political ad buys have ignored the unfolding story of campaign cash on their newscasts.

The report found that even as local newscasts have set aside significant time to cover the campaign season, they have set aside virtually no time to examine who's sponsoring the thousands of campaign ads the stations are airing, which special interests the ads represent, or if any of the claims presented in the (mostly negative) commercial are accurate.

From the Free Press report by Tim Karr, “Left in the Dark”:

The lack of reporting on political ad spending is egregious given just how many political ads these stations air -- ads that are producing record revenues for station owners. This profiteering may explain broadcasters' reluctance to investigate the relationship between political ad spending and local media.

The study examined local campaign news coverage that's aired in the swing state markets of Milwaukee, Charlotte, Tampa, Cleveland and Tampa.

Among Free Press' key findings:

• Most affiliates in those markets didn't fact-check any of the claims made in campaign ads placed by the four Super PACs and independent groups spending the most in those markets.

• Cleveland's four affiliate stations provided no August coverage on the Koch brothers-funded group Americans for Prosperity, despite the group airing 500 anti-Obama attack ads locally at the time.

•  In Charlotte, the four TV affiliate stations provided no local reporting in August on the three top-spending political groups (American Crossroads, Americans for Prosperity and Restore Our Future), which, combined, spent more than $4 million on Charlotte ads that month.

As Free Press stressed, television continues to be the dominant source of news and information for consumers, and local stations can play a key role in that coverage. During the campaign season, those stations ought to do more than simply count the receipts from all the political cash pouring in. They have a responsibility to report on who's paying those massive bills and what their message is.

Note: Founder and Chairman of the Board David Brock has founded and serves as Chairman of American Bridge 21st Century, a 527 “superPAC” unaffiliated with Media Matters.