When a group of sports bar owners led by a San Diego hot dog vendor threatened to mount a national boycott of network sponsors over plans of CBS and NBC to scramble their satellite transmissions of professional football games, the two networks promptly gave in, at least for this season.

The networks' capitulation earlier this month to the noisy interest group -- and to network advertisers, including Anheuser-Busch Companies Inc. and Miller Brewing Co., whose businesses were threatened by the boycott -- reflects a new willingness on the part of corporations to respond to proliferating consumer boycott movements like that of the sports bar owners.

"It used to take years for companies to even recognize that they were being boycotted," said Todd Putnam, editor of the Seattle-based National Boycott News, a six-year-old publication that tracks consumer protests. "Companies are becoming more defensive" than they used to be.

Putnam attributes companies' growing sensitivity to product boycotts to sheer numbers. There are more than 70 groups around the country currently sponsoring or cosponsoring 200 to 300 boycotts, twice as many as were being mounted this time a year ago. Heightened environmental awareness is the force behind most of the consumer movements, he added.

This year, Putnam said, "is shaping up to me to be the year of the boycott."

The leader of the sports bar boycott was Norman Lebovitz, owner of Sluggo's, a San Diego hot dog eatery that features satellite broadcasts of Chicago professional sports games. He said the networks' plan, announced last month, to scramble National Football League broadcasts would seriously have damaged his restaurant business.

Lebovitz quickly enlisted the support of hundreds of other sports bar owners nationwide who were in the same predicament, and they threatened to boycott the products of several NFL network sponsors, including Anheuser-Busch, Miller, and Sears, Roebuck & Co.

Miller was concerned enough about the prospect of a boycott to fly Lebovitz to New York to meet with network executives, an example of what Miller spokesman Dave Fogelson said is his company's willingness to listen to the concerns of its customers and retailers.

"We consider what they say, and we respond accordingly," Fogelson said. "But the response isn't always going to be the same."

Lebovitz said he was relieved when the networks said that they were suspending NFL scrambling until next year at the earliest.

"My heart wasn't really in this. Being a retailer all my life, I really had no desire to hurt anybody," Lebovitz said.

Responding to such threats does not always mean that the companies are giving in. Nike Inc. demonstrated that with its defiant posture in the face of Operation PUSH's recently announced boycott of Nike's shoe and sportswear products. Nike claimed that the civil rights group had been influenced by donations from its leading competitor, Reebok International Ltd. Operation PUSH denied the charge.

Boycotting has become so legitimate that even corporations are using it. Earlier this year, Procter & Gamble Co. canceled all advertising with a Boston TV station, WHDH-TV, after the station carried advertisements produced by Neighbor to Neighbor, a San Francisco-based group that urged viewers not to buy Folger's coffee, a P&G subsidiary. The ads criticized P&G for using El Salvadoran beans in its products.

Don Tassone, a spokesman for P&G, said his company believes in the right of groups like Neighbor to Neighbor to protest corporate actions and even to mount boycotts. "But this was a very offensive piece of advertising," he said, adding that P&G would cancel ads with any other station that ran the anti-Folgers spots. "This is not the type of environment in which we'd choose to advertise our products," Tassone said.

A key to how, or if, a company will respond to a boycott threat is whether or not it believes customers will be sympathetic to the motivation for the boycott and its sponsors, said Phil Wilbur, the director of the Heath Advocacy Center in Washington, which provides strategic and research assistance to a variety of public interest groups, particularly those involved with alcohol- and tobacco-related issues.

But Wilbur said boycotts are generally not effective tools for these groups because persuading consumers to forgo those products is not a realistic goal.

"With cigarettes, in particular, it's an addictive product," he said. "It's not something you can quit doing spur of the moment."

But Wilbur said one group the center has worked with that may actually have some success with its boycott is the AIDS Coalition to Unleash Power, or ACT UP, which has targeted Marlboro cigarettes and Miller beer to protest parent company Philip Morris Inc.'s financial support of Jesse Helms, the conservative North Carolina senator who they say has stood in the way of AIDS research funding.

Michael Petrelis, an organizer with the Washington ACT UP chapter that started the boycott, said Philip Morris sent two executives to Washington to meet with his group. But so far, Philip Morris has stood by its financial support for the senator.

Alice McGillion, Philip Morris's director of communications in New York, said the two executives' trip was part of the company's overall response strategy to the boycott, which is primarily educational. "We have spent a lot of time and effort trying to explain our position to the gay community," she said.

Putnam said another reason he believes boycotters are having more luck getting companies' attention is that today's boycotters are threatening companies' images, not just their pocket books.

And image damage can create long-term problems for companies, hurting morale within the company and making it difficult to recruit employees. As a result, some companies targeted by boycotters have responded by trying to attack the image and credibility of the boycotters.

While the groups that mount boycotts represent a wide variety of interests, Putnam said a majority of the current efforts are environmentally motivated.

In the five months after the tanker Exxon Valdez dumped 10 million gallons of oil into Alaska's Prince William Sound in March 1989, nearly 40,000 of Exxon's 7 million credit card holders returned their cards to protest the spill and the company's cleanup effort.

Exxon responded with a series of frank advertisements that ran in more than 100 newspapers around the country. The ads emphasized that most Exxon stations were privately owned and that these businesses would bear the brunt of the boycott, not the oil company.

Boycotts also frequently stem from labor disputes, Putnam said.