Why won't the Wing Bowl sell? The belchfest has trouble attracting national ads. "It's kind of gross," says one ad specialist.

You'd think that when the WIP Wing Bowl belches to a start tomorrow morning, the Wachovia Center stage would be loaded not just with hungry men and barely clad women, but with banners for national sponsors.

Maybe Pepto-Bismol. Or Tums. Or ExxonMobil, like Wing Bowl a major producer of gas. Why not a life-insurance company, say, Chubb?

With 25 contestants and 20,000 onlookers, Philadelphia's annual bacchanal is among the biggest eating contests in the country, drawing bellyfuls of local advertisers, including Apple Vacations, Steven Singer Jewelers, and the Matt Blatt auto dealerships. But like similar events it struggles to attract national ad dollars.

The big boys, it seems, just don't have an appetite for competitive eating.

"National advertisers are often looking for critical mass beyond one local market," said Marc Rayfield, vice president and general manager of WIP-AM (610). "I don't look at it like, 'Why can't we get more national sponsors?' I look at it as, 'What's realistic?' "

And that means concentrating on regional companies, he said.

Amazingly, there are mega-brands that think it unwise to associate themselves with gluttony, drunkenness and breast-flashing, not to mention obesity, a health problem that afflicts 60 million Americans.

But marketing experts say large companies are queasy for other reasons as well.

Competitive-eating events, even tame ones - which the Wing Bowl is not - don't convey an image of pinstripes and power ties. They're about BMI, not IBM, experts say.

The complexity of running a national ad campaign makes it difficult for firms to sign on with local events, no matter how popular.

And as risky as it can be for advertisers to hitch their product to a celebrity pitchman - not even movie stars look good in handcuffs - public events can be hazardous, too.

In California last month, a 28-year-old woman downed bottle after bottle in a radio station water-drinking contest - and died hours later of water intoxication. Now police are pursuing a criminal investigation, the woman's family plans to sue, and 10 station employees have been fired.

"The people who run the 'sport' have been trying very hard to make it safe for corporate America, and they've gotten halfway there," said Jason Fagone, the Philadelphia author of Horsemen of the Esophagus: Competitive Eating and the Big Fat American Dream.

"It could get to a point where it's family-friendly enough to attract decent crowds and make the advertiser feel safe enough to invest," Fagone said. "Or you could have somebody choke and die. It's happened a couple of times in Japan."

Having a competitor keel over on stage - and seeing the video replayed in an endless YouTube afterlife - isn't good for business.

Wing Bowl, Fagone said, is "a national advertiser's worst nightmare," with "things being thrown, guys drunk and passing out."

"I think WIP realizes they're stuck. If they tone it down to make it family-friendly, then they lose what made it popular."

And Wing Bowl is nothing if not popular. The $5 tickets to Wing Bowl 15, presented by PhiladelphiaPark Casino, sold out in a day. So did seats to last year's contest, where Joey Chestnut tasted victory by consuming 173 wings in 30 minutes. (That's a wing every 10.4 seconds.)

Tomorrow's event starts at 6 a.m., and will be broadcast on Sportstalk 610 by cocreators Al Morganti and Angelo Cataldi.

Steven Singer, owner of the Jewelers' Row emporium that bears his name, is a longtime Wing Bowl sponsor. Singer said he loves the excitement, loves Cataldi, loves how the event attracts both neurosurgeons and pole-dancers.

But as a businessman, Singer said, the bottom line is that the Wing Bowl drives sales.

"We get a ton of business from it," he said. "That day, the next day, that weekend. And that leads right into Valentine's Day for us."

Competitive eating, in which contestants down stomach-bursting quantities of hot dogs, burritos, oysters or even sticks of butter, has been covered on ESPN, written up in Sports Illustrated, examined in books, dissected in documentaries. It even has its own governing body, the International Federation of Competitive Eating, which ranks the top eaters.

George Shea, federation chairman, said the sport's biggest sponsor is Nathan's Famous Inc., the hot dog company. The firm, with about $41 million in annual sales, holds a July 4 hot-dog-eating contest at Coney Island, attended last year by an estimated 25,000 fans.

Previously, the sport's biggest sponsor was Alka-Seltzer, which put on the U.S. Open of Competitive Eating in 2005, but has since withdrawn.

Why haven't other national brands signed on?

"I don't know," Shea says. "It may be the target audience. If you're targeting moms, you have to have a different play."

Competitive eating also suffers from a blurred identity. It's not an athletic competition like pole-vaulting, not a game of skill like pool, not a test of intellect like chess.

Plus, "it's kind of gross," said Kelly O'Keefe, executive education director of Adcenter, the graduate program in advertising at Virginia Commonwealth University. But the contests do attract tremendous attention, he said.

Audiences tend to be male, aged 18 to 35, and certain firms can capitalize on that. How about Burger King, which has shown a readiness to embrace the absurd with ads featuring its plastic-headed king? How about a men's magazine like Maxim? Why not Hooters? That way you would have wings and breasts, O'Keefe noted.

"National sponsors will come," he said. "Maybe not this year, but it's on its way."

David Fields isn't so sure.

The managing director of Ascendant Consulting L.L.C. said the reason big advertisers don't bite on events like Wing Bowl has less to do with guilt-by-association than with the mechanics of ad purchasing. Despite the fragmentation of the media, he said, national firms still favor big up-front buys of network TV time. It's impossible for a company to sponsor one event in Philadelphia, another in Indianapolis, a third somewhere else.

WIP's Rayfield said he saw that firsthand while working at KYW Newsradio. He expected a natural marriage between the station's popular snow-closing report and the cold-and-flu remedies made by locally headquartered pharmaceutical firms.

"Their response was always, 'Hey, we understand, we think it's terrific, but we're selling national products.' "

So, for Wing Bowl, Rayfield courts local advertisers and waits for the other guys to realize what they're missing. This year WIP came close to signing a national TV deal, he said, and next year he hopes to do more than come close.

"As the person responsible for the event, I like to think I get a little smarter every year," he said. "Each year it gets bigger, the publicity spreads wider. We'll keep figuring out better ways to monetize it. But you sort of go where the fish are."

For video of this year's Wing Bowl qualifiers - and non-qualifiers - as well as video of the Wingettes and other event information, go to http://go.philly.com/wingbowl

Contact staff writer Jeff Gammage at 610-313-8110 or jgammage@phillynews.com.