Forget the strategists. Forget the campaign advisers and the pollsters. Now is the time in the campaign when a low-profile and little-understood player wields a great deal of influence: the media buyer.

The beginning of September through mid-October of an election year is the most crucial period when it comes to moving TV ad reservations, buying new ad time and finding out what spending decisions the other party is making. Media buyers play an integral role in this process, despite the fact that they rarely gain any public recognition for their work.

By the time Election Day arrives, Kantar Media/CMAG estimates in Ad Age that 3.6 million television ads will have passed through these media buyers’ hands – as campaign spending on the 2012 elections is expected to reach unprecedented levels.

Media buyers are number-crunching creatures obsessed with ratings and demographics. The objective is to maximize a campaign’s resources when buying advertising from local television affiliates across the country. The job is part journalist, part spy, part demographer and part network scheduler.

But the media buyer’s true value to a campaign is the proprietary knowledge that only he and his colleagues traffic in: how the opposition is spending – or not spending – its ad dollars on television, particularly during the homestretch of a race. What a buyer knows and how quickly that information is communicated could mean life or death for a political career.

“If the [National Republican Congressional Committee] was attacking one of our clients and stopped, we would know that in hours,” a Democratic media buyer said. In this scenario, if a political committee stops running ads to attack a candidate, it likely means the attacks aren’t working and that the money would be better spent elsewhere.

Go to any media buyer website, and one will learn all about how that firm can most effectively target audiences with a campaign’s money. If a campaign needs to reach a specific group of people, media buyers will absorb ratings data and decide which channel, show and time slot is the best platform for a campaign’s message. They will then contact local stations and buy the advertising time on behalf of a campaign.

Timing is everything. It is all a poker game. A media buyer wants to buy early enough to lock in lower rates, but not so early as to telegraph a campaign’s strategy.

“After planning the buy, the goal is to wait as long as possible to pull the trigger so that you stay under the radar,” said a Texas GOP operative familiar with the process. “However, waiting too long can backfire, as there might not be enough space left.”

The intrigue starts when communication goes in the other direction.  

Political ad spending is legally public information. Some television affiliates’ sales information is on the Federal Communications Commission website, but mostly the information is stored in hard-copy form in file cabinets at local television stations.

A good media buyer has deep professional relationships with the sales executives of local television stations and uses those ties as a form of reconnaissance. One Republican media buyer said the information flow about advertising spending and placement is no different from what occurs in other competitive industries.

“Don’t think GM doesn’t know where Ford is spending every one of their dollars,” he said.

As the media buyer and sales representative talk about the business they’re doing together, the buyer constantly prods the sales representative about what buys the opposing campaign is making. Because the information will eventually be public anyway, and in order to maintain that relationship, the sales representative often tells the buyer about ad reservation changes coming from the other campaign.

Republicans and Democrats agree that there is no ideological motive at play for the sales representative.  

As soon as a reservation is upped or canceled, the sales representative will call the opposition media buyer. The media buyer will then relay the information to campaigns, and phones ring all the way to Washington, D.C.

Whether  a national party committee opts to invest money in a race is a direct reflection of its confidence in a candidate. The information is usually stored on Excel sheets. National operatives are able to confidently rattle off on cue the amount of money each side is spending.

“It’s definitely part of their value – having accurate information that is quickly accessible,” one national GOP strategist said.

The most dramatic information that a media buyer can obtain is when a campaign committee has completely canceled ad reservations in support of a candidate, also known as “triage.” The word triage means more than a decline in ads. The metaphor relates to a flooded emergency room, where doctors must decide which patients can be saved and which ones can’t.

But ad tracking is not an exact science. Media buyers place a premium on never being wrong, but this is human intelligence.

Amid all of this information gathering and sharing, not every sales representative is game. The national GOP strategist went so far as to call some television stations “ornery.” But it takes just one person in a media market of four or five stations to flag a change in the opponent’s ad buy.

“There’s enormous pressure for us to be right, but at the same time you have to weigh that against being fast,” the Republican media buyer said.

Most of the media buyers interviewed for this story seemed surprised there was any interest in their profession.

Sometimes they work for large companies that monitor races across the country. Others operate regionally. And some media consultants do their own media buying in-house.

They typically come from an advertising or political background and then learn the other side along the way. Republican or Democrat, they usually described their lives as borderline nerdy.

But in politics, there is always a certain glamour to being the first to know anything.