Progressive blogs have been atwitter this week with the news that Glenn Beck's program is hemorrhaging advertisers—thanks to the host's infamous comment that President Obama is a “racist” who harbors a “deep-seated hatred for white people."

The ad exodus was sparked by an anti-Beck campaign led by an activist group called Color of Change, an Internet-based organization dedicated to amplifying black America’s voice in the political arena. The group circulated a petition asking companies to withdraw their ads from the program; thus far, it’s garnered more than 280,000 signatures. To date, the group says 80 companies have dropped their ads from the show—many of which explicitly condemned Beck in announcing their decision. Among them: Procter & Gamble, Geico, and AT&T. Recently, several sponsors of Beck’s broadcasts in England have joined the campaign—including Tanqueray and supermarket giant Waitrose.

Fox is unlikely to worry too much about Beck’s viability unless or until he starts losing viewers as well. “If there are high ratings and it’s a good buy, some advertisers will migrate toward the program anyway,” Marquette University Professor Lawrence Soley said.

The campaign’s success has stirred hopes in liberal circles that it might actually might cripple Beck commercially—and force his show off the air. Huffington Post blogger Ben Cohen predicted Monday that Rupert Murdoch “is probably crunching numbers to see how viable Beck is to Fox News in the long run” and would eventually decide to cut him loose.

But several media experts interviewed by The Daily Beast suggest that the Beck boycott is unlikely to do much long-term damage. Nor does Color of Change expect Beck to be fired thanks to its campaign—at least not any time soon.

The principal reason: Beck's gangbuster ratings. They've only gone up since the controversy began in August, as his ultraconservative audience, spurred by encouragement from fans like Sarah Palin, has rallied to his defense. A similar boycott campaign against Dr. Laura Schlesinger—for remarks seen as hostile to gays—succeeded in scaring off advertisers and eventually knocked her off the air in 2000. But the radio host's TV show was already suffering from weak numbers. In another case with similarities, Rush Limbaugh was forced to resign his ESPN commentator post in 2003 after racial remarks about football star Donovan McNabb. But unlike ESPN, which caters to an ethnically and politically diverse audience of sports lovers, Fox News has a much more homogenous audience, with few liberals who might threaten to change the channel over Beck's controversial words.

According to Marquette University Professor Lawrence Soley, author of Advertising Censorship, Fox is unlikely to worry too much about Beck’s viability unless or until he starts losing viewers as well.

“If there are high ratings and it's a good buy, some advertisers will migrate toward the program anyway,” Soley said. “And if it is a highly rated program, some of the advertisers who withdrew probably will contemplate going back at a future time and don't want to burn their bridges with Fox.”

Still, observers are watching to see whether Beck’s show starts attracting a different sort of advertiser. As Gawker recently noted, Beck's sponsors lately are not exactly the Fortune 500 types, featuring instead such businesses as Extenze penis-enlargement pills.

“If you don’t see the GMs and the Sprints and the big movie companies [advertising on Beck] and you see Cash4Gold.com instead, that's bad. But with Fox you can carry a lot, especially if the numbers are up,” MediaPost Communications' West Coast editor, Wayne Friedman, told The Daily Beast.

Fox maintains that the anti-Beck campaign has had little impact because advertisers are merely shifting to other shows on the network. Despite claims from Color of Change, which are based on anonymous industry sources who say the advertising pullout was having a significant effect on revenue, Fox News has publicly denied that they have lost money. "The Color of Change figures are wildly inaccurate on all fronts—revenue has not been affected in any way," a Fox spokesperson told Mediabistro. Asked by The Daily Beast for comment, a Fox News spokeswoman said nothing had changed since their previous statement.

Given that Fox shows cater to relatively similar demographics, experts say it's less difficult for them to find acceptable alternative spots for advertisers than it would be at other networks with a more varied lineup.

“Unlike broadcast networks where there's limited inventory in prime-time and daytime, you really have 24 hours on a cable network and plenty of places to put that ad somewhere else,” Friedman said.

According to Color of Change co-founder James Rucker, the petition is part of a long-term campaign to isolate Fox News and turn Beck into a liability.

“I don't believe he's necessarily going to be off the air, at least in terms of just the [current campaign],” Rucker said in an interview. But he said he expected the campaign to hurt Fox's bottom line, despite the networks' claims to the contrary.

“Fox has maintained that given the nature of existing contracts, they're not yet losing revenue. Over time, however, it will go down,” he said. “The flipside is his ratings have gone up, but his ratings don't necessarily turn into dollars.”

The hope, according to Rucker, is that Beck threatens to contaminate Fox News' overall brand. If the network becomes sufficiently associated with race-baiting and other questionable practices, he posits, Fox could find itself losing access to sources on its editorial side and scaring off even more advertisers on its business side. Already, Fox has battled with the White House press team, who called out Beck by name for getting facts wrong in a news report on the Olympics. Recently the White House declined to grant the network an interview with the president during a media blitz that included every other major news channel. Earlier this year, Obama described the network as “entirely devoted to attacking my administration.”

“If it becomes a Fox story and not a Glenn Beck story, then it's a strategic problem for Fox,” Rucker said. “They take comfort in being perceived as, to be nice about it, right wing. I don't think they can be comfortable in being perceived as the sole network that condones and, in fact, encourages active fearmongering and race-baiting. I think that would be a liability.”

In the meantime, Beck can do damage of his own. Just ask Van Jones, Color of Change's co-founder, who left the organization the year before becoming the White House's "green-jobs czar"—only to resign in the face of a Beck campaign against him. The talk-show host targeted Jones’ past activism, and turned up his signature on a petition questioning whether President George W. Bush was behind the 9/11 attacks.

Benjamin Sarlin is a reporter for The Daily Beast. He previously covered New York City politics for The New York Sun and has worked for talkingpointsmemo.com.