(CNN) -- Iowa's 2.3 million eligible voters have been bombarded with close to $40 million worth of political ads on television this cycle -- more than three times the amount spent there in 2004.
Sen. Barack Obama leads all candidates in TV ad spending during this election cycle.
That works out roughly to about $17 per voter, between $150 and $200 per expected caucus-goer, and nearly $500,000 per each of the state's 82 delegates in a contest that -- unlike 2004 -- is wide open on both sides of the aisle.
But what Iowa might lack in population and size, it makes up for in primary calendar position -- especially in this truncated cycle when well over half the states will have held their primary contests on or before February 5.
Early momentum -- or lack of it -- is more likely to make or break a presidential bid.
As a result, presidential candidates and third-party organizations are forced to define their message sooner than ever, and the first wave of states may be their only chance to do it.
"Iowa has become much more than just an organizational test, it's clearly become a message test, and TV is the biggest amplifier for getting messages out," said Evan Tracey, chief operating officer of TNS Media Intelligence/CMAG, CNN's consultant on campaign television advertising spending.
"If you put a bunch of states together like what has happened on February 5, all the campaigns don't have the money to have any sustained message presence or TV presence in those states," Tracey added, "So essentially it leaves them more money to do what they want to do in Iowa, New Hampshire, and South Carolina."
But how many individual ads are needed to convey a message? According to an analysis by CMAG, more than 50,000 spots have aired in Iowa this cycle through December 29, with a final blitz expected in the days before the caucuses.
On December 18 alone, 1,093 campaign ads aired on Iowa television, largely in the four major media markets in the state. That equals more than nine solid hours of commercials in 24 hours.
"Every time you turn on your television, you're seeing a political ad of some sort, they are unavoidable," Tracey said.
Democratic Sen. Barack Obama of Illinois far outpaces any other candidate when it comes to ad spending in Iowa, having spent more than $9 million on close to 11,000 spots. That's about $2 million more than Sen. Hillary Clinton of New York has spent ($7.2 million), and about three times the amount that former Sen. John Edwards of North Carolina has shelled out ($3.2 million). Clinton has aired close to 8,000 spots while Edwards has aired 3,700.
On the Republican side, former Massachusetts Gov. Mitt Romney has spent close to $7 million for 8,500 spots, about five times more than former Arkansas Gov. Mike Huckabee has spent ($1.4 million) for 1,800 ads. Former Sen. Fred Thompson of Tennessee is close behind, spending $1.1 million for 1,100 ads.
Two leading Republicans have been noticeably absent from Iowa airwaves: Sen. John McCain of Arizona and former New York Mayor Rudy Giuliani. Both have made the risky gambit of largely skipping Iowa to focus on later states -- McCain on New Hampshire, which votes five days after Iowa, and Giuliani on Florida, which holds its nominating contest January 29.
But despite the disparity in ad spending among the leading candidates in Iowa, the latest Iowa polls show a deadlock on both sides -- an indication the race won't be won just on the Iowa airwaves.
This is most evident in the case of Huckabee. Several polls have shown him leading or tied with Romney despite being outspent on TV. Hucakbee's success in the state is largely due to his favorability among the evangelicals who constitute a major portion of Republican voters there -- a constituency that isn't likely to be swayed by television ads alone.
"With [Kansas Sen.] Sam Brownback dropping out, and to a lesser extent Newt Gingrich not getting in, Huckabee won the [evangelical] primary by default; that's never a TV primary," Tracey said.
But the massive candidate expenditures in Iowa are only half the story. Third-party organizations -- some of whose campaign funds are unregulated and not tied to donation caps -- have spent heavily in Iowa.
Edwards and Clinton are largely the beneficiaries of these groups' spending on the Democratic side.
The American Federation of State, County and Municipal Employees, the major union organization that has endorsed Clinton, has spent close to $700,000 on ads, while Alliance for a New America -- a Service Employees International Union political action committee headed by Edwards' former campaign aide Nick Baldick -- has spent nearly $250,000 on behalf of Edwards. Edwards is also the beneficiary of $364,467 worth of ad spending from Working for Working Americans, a United Brotherhood of Carpenters Union PAC.
Obama, the target of many of the third-party ads, especially those from Alliance For a New America, has directly called on Edwards to denounce the spots and has used the issue on the stump as evidence the former senator is not the fighter of special interests he claims to be.
"You can't say yesterday you don't believe in it, and today three-quarters of a million dollars is being spent for you," Obama has said. "You can't just talk the talk. Everybody talks change, but how did they act when it was not convenient, when it's hard?"
Edwards has said he is against the ads, but says it is against federal election laws to contact the PAC directly to ask them to discontinue the spots.
On the Republican side, third-party ads have largely targeted Mike Huckabee. Most of those have come almost entirely from the anti-tax group Club For Growth. The organization, which has given Huckabee a dismal gubernatorial ranking, has spent close to $320,000 assailing the Arkansas Republican's record on taxes.
But Tracey is skeptical that the third-party spending will have any significant impact on how Iowans vote come caucus night.
"I think all they do at this point is add a few more logs to the fire," he said. "I don't think they necessarily change the dynamic, for the most part all they did was add more background elevator music."
Come Friday, most Iowans will no doubt be relieved when the background music finally falls silent. E-mail to a friend