Rep. Ron Paul’s campaign made the biggest effort to appeal to a broader slice of the Iowa electorate. Paul’s campaign, which relies on irregular voters and disaffected populations who don’t otherwise turn out to cast ballots, targeted viewers on 20 different cable networks—channels as diverse as the Food Network, the Golf Channel, the History Channel, and Spike and FX, two outlets that cater to younger male audiences with sports and talk shows. Paul’s campaign even spent about $2,400 on 36 spots on The Weather Channel in the Columbia, Florence and Myrtle Beach and Greenville-Spartanburg markets in South Carolina.

Other candidates didn’t have the resources Romney or Paul brought to the advertising game. But one advantage of advertising on cable is that high-impact spots, when they become available, can sell for much less than broadcast ads. Former House Speaker Newt Gingrich took advantage of one of those rare moments; on December 29 of last year, Gingrich placed significant ad buys on ESPN and ESPN2 in nine Iowa markets. That day, the Iowa State Cyclones lost the New Era Pinstripe Bowl to Rutgers and the Iowa Hawkeyes were overrun by the Oklahoma Sooners in the Insight Bowl. Both games aired on ESPN, giving Gingrich relatively inexpensive access to every college football fan in Iowa.

Texas Gov. Rick Perry’s campaign bought cable advertisements in November and December for an even more specific audience tuning into the Big Ten Network, a station that broadcasts sporting events from around the Midwest (The University of Iowa is in the Big Ten). Buying sporting events gave both Gingrich and Perry access to overwhelmingly male, Republican leaning audiences—cheap, effective surgical strikes.

Even while cable is growing, broadcast television remains the dominant medium, according to advertising experts in both parties and the industry itself. And yet cable is playing a bigger role, especially for those who need demographic metrics to back up their investment.

“If I want to target viewers between the ages of 25 and 64 through cable news, I know that ‘The O’Reilly Factor’ reaches the most viewers for that age group,” says Laura Crawford, a media buyer at JDA Frontline, a Republican firm. “With cable we can microtarget not only age groups, but those who have interest in fitness, food, specific sports, and reality TV.”

Given the mega-budgets outside groups and the campaigns themselves are planning for key races across the nation, cable also plays a big role in establishing a narrative. Airing inexpensive ads is a cheap way to back up messages that come through in other media.

“It’s largely seen as a supporting tool. So if you’re running mail, you’re using cable to back up the mail. If you’re running broadcast, you’re using cable to back up the broadcast,” says Walsh. “You can use it to reinforce your broader message and/or in some cases microtarget your message to specific audiences.”

Walsh, who served as political director at the National Republican Congressional Committee in the 2010 cycle, pointed to Gov. Chris Christie’s successful bid in New Jersey in 2009 as one example.

Incumbent Democrat Jon Corzine had accused Christie of jeopardizing mammogram coverage in health insurance plans; Christie blasted back on cable. Christie’s response credited a mammogram with saving his mother’s life by detecting breast cancer early. The spot ran on cable channels almost exclusively targeted toward women voters.

And thanks to new and popular election laws, buying cable is becoming even more important as voters consider their options. In many states, absentee ballots begin arriving in mailboxes as much as a month before Election Day (In Washington State and Oregon, elections are conducted entirely by mail). With a growing percentage of Americans voting early, Election Day no longer takes place on one day—it takes place over four weeks. That presents a campaign with budgetary problems.