Discovery channels: in the marketplace, truth is always a hot commodity.

The New Republic fires Associate Editor Stephen Glass after discovering he invented sources and subjects for more than two dozen stories he wrote for the magazine. The Boston Globe dismisses columnist Patricia Smith after finding out she also created fictional characters to deliver polemical messages in her "reporting" about life on the streets. CNN and Time make a dramatic public apology and retraction - and fire two producers - after jointly airing and publishing stories alleging that the U.S. military used nerve gas on American deserters in Vietnam.

Prestige press outlets have taken some serious body blows over the past few months. And media critics have quickly fingered the cause of these missteps: capitalism - or more precisely, the lust to capture readers and viewers in a hypercompetitive marketplace.

In the Los Angeles Times, former CBS and NBC reporter Marvin Kalb, now a professor at Harvard's Kennedy School of Government, blames "profit-centered, business-oriented news" and the "24-hour-a-day news cycle with nonstop demands for 'profitable news.' "In Intellectualcapital.com, media critic Eric Alterman faults the "culture of celebrity worship" and "the notion that the actual information in any given story is less important than the entertainment package it helps create." Wired's Jon Katz complains that "the business of journalism has become dominated by large conglomerates whose only interest is profits, who have no ideology other than mass marketing."

Joseph Pulitzer and William Randolph Hearst must be cackling from their graves. A century ago, the two icons of contemporary prestige journalism drove the nation into a frenzy - and a war with Spain - with their sensationally exaggerated accounts of Spanish oppression in Cuba. Their goal was to sell newspapers with what became known as yellow journalism. From the colonial pamphleteers who fomented revolution against the British to the frontier editors who would publish any slander to sell papers (as recounted in Mark Twain's hilarious early story "Journalism in Tennessee"), "newspapermen" and broadcasters have always sought bigger audiences and fatter profits by offering information and entertainment.

The current controversies are different in one important way: The competitive processes of today's marketplace led to the rapid exposure and resolution of these journalistic shenanigans. Rather than denigrate capitalism and the search for profits, media critics should praise market processes for providing a public service. The desire to discover the truth, and to place reputation ahead of short-term notoriety, exposed all three frauds.

Glass's follies were made public by an editor for the online publication Forbes Digital Tool. Adam Penenberg covers technology companies, and when he read a story Glass wrote about young computer hackers working for high-tech firms, something seemed fishy. Penenberg discovered that a company described in the article didn't exist - and neither did the hackers. Penenberg then approached TNR Editor Charles Lane with this information, and after conducting his own investigation, Lane gave Glass the heave-ho.

Patricia Smith's fabrications were discovered internally, but the Globe wasted little time getting rid of her in a very public way before she could further damage the paper's credibility - and its bottom line. And when outraged veteran groups and skeptical military analysts flooded CNN and Time with questions about their story on nerve gas attacks in Vietnam, CNN - a relative newcomer in the media business - feared that its reputation as a source of news might be irreparably damaged. It hired respected First Amendment lawyer Floyd Abrams to check out the criticisms. Abrams found the story shabbily reported and concluded it should never have been aired.

CNN's Ted Turner announced the creation of an ombusdman-like office that will vet future investigative stories before the network airs them. But the controversy continues, primarily because CNN didn't fire correspondent Peter Arnett, and media watchdogs are still hounding CNN.

Not so long ago, most people got pretty much all their news from the big three networks and their local daily newspaper. It was a great system for those fortunate enough to land the few available jobs. And many who work in today's prestige media prefer the old regime. Now, laments Kalb, NBC and its cable outlets MSNBC and CNBC offer 27 hours of national news every day; most network affiliates add two to three additional hours of local news.

And that's just one media group: C-Span, CNN, Fox, PBS, NPR, all-news radio channels, radio talk shows, and Web pages that link to wire services offer plenty more viewing and listening options. These additional outlets serve as feedback mechanisms, constantly vying to offer more information, a different take on a story, a new angle that can clarify a complicated issue. There are more opportunities for enterprising journalists to build reputations for themselves and their publishers.

A 24-hour market now serves news junkies, and it offers a new set of challenges for those who provide information to the public. There's more time to fill, which places a premium on providing material worth watching. Channel- (and Web-) surfing audiences are fickle; they can easily go elsewhere if they feel they're not being informed or entertained.

But these peripatetic viewers are also less likely to accept what they see without question, especially when hundreds of alternatives bid for their time and attention. And there's actually more pressure on reporters and editors to be careful in verifying stories before airing or publishing them: If a media outlet gets something wrong, there are countless competitors eager to point out mistakes before their news-hungry audiences.

If Kalb, Alterman, and Katz were truly public-spirited, they would celebrate the current competitive atmosphere: The "nonstop demand for profitable news" encourages correction of error and dissemination of truth. The quest to maintain credibility leads media outlets to investigate their own work. In the marketplace, reputation is one major factor that separates prestigious institutions from fly-by-night operators and other fast-buck artists. Competitive forces have broken up the near-monopoly powers the big media providers once enjoyed. As with the end of any monopoly, consumers - in this case, news lovers - are the ultimate victors.