Here's the campaign. Where are the ads?

DES MOINES, Iowa (CNNMoney) -- The 2012 Republican primary campaign has already produced its share of carefully crafted messages, political drama and mudslinging.

But not much of that action has played out during commercial breaks in early selection states such as Iowa, New Hampshire and South Carolina.

That's because spending on political ads -- usually a hallmark of campaign strategy -- has fallen off a cliff.

"I've never seen anything quite like this," said Paul Frederickson, a 38-year veteran of the television business and general manager at KCCI in Des Moines.

The station has experienced about a 50% drop in the number of purchased political ads, according to Amanda Hull, KCCI's general sales manager.

"It's a huge deficit to fill when you're planning for your budgets and you need that revenue to be coming in," Hull said.

According to an estimate of political ad buys from Campaign Media Analysis Group (CMAG), spending in Iowa is down nearly 85% from last cycle. That figure includes spending by candidates and political action committees, but does not account for spot cable advertisements.

The trend is not just playing out in Des Moines -- it's everywhere. Nationwide, CMAG estimates suggest spending is down as much as 60% when compared to the 2008 campaign.

"Candidates are probably spending a quarter as much money -- just on the Republican side," said Ken Goldstein, president of CMAG. "It's getting intense now, but it's not going to make up for the ads that weren't on the air in September and October."

Campaign watchers say there are a few possible reasons for the drop in advertising.

First, there have been more debates held this year than any other in recent memory. And for candidates, that means a ton of free airtime.

America's Choice 2012

Goldstein said debates usually allow candidates to receive three days free coverage, as news channels run stories leading up to, during, and after the debate.

And since the Republican primary has been relatively drama-filled, the number of news stories produced on candidates has increased, resulting in more cost-free airtime.

In Iowa, there is another reason sales will be lower this year: the compressed early caucus and primary schedule.

The state's caucus, the first in the country, was initially scheduled to take place in February, but jockeying among other early states forced Iowa to move the date up to Jan. 3.

Swing state economies complicate 2012 picture

That has repercussions beyond just politics, as local merchants are finding it difficult to place ads during December, a crucial time of the year for the retail industry.

"We do hear complaints from regular advertisers," said Hull, who added that the station must run political ads because of Federal Communications Commission requirements that mandate equal airtime for candidates.

Even with diminished spending, political spots can still take up half of all ads during local news broadcasts. Just before the primary, every ad during key programs could be for one candidate or another.

For the average Iowan, that can get a little old.

"Every time I flip on the TV it's one ad after another. You flip the channel hoping to get away from it and you see more ads," said Emily Heetland, a teacher.

"I don't like watching them," she said. "I get sick of them."

-- CNNMoney Associate Producer Jordan Malter contributed to this report.