TOKYO — For years, the online newspaper JanJan News mounted a scrappy challenge to Japan’s blandly conformist press, offering articles written by readers who took on taboo subjects like whaling and the media’s collusion with the government. The site never attracted enough readers or advertising, though, and was finally forced to shut down most of its operationsthree months ago.

JanJan was the last of four online newspapers offering reader-generated articles that were started with great fanfare here, but they have all closed or had to scale back their operations in the past two years.

And it is not just the so-called citizen journalism sites that have failed here. No online journalism of any kind has yet posed a significant challenge to Japan’s monolithic but sclerotic news media.

"Japan just wasn’t ready yet," said JanJan’s president and founder, Ken Takeuchi, a former reformist mayor and newspaper journalist who started the site in 2003. "This is a hard place to create an alternative source of news."

While Japan’s long economic stagnation has prompted a slow dismantling of the nation’s postwar order, punctuated by a historic change of government last year, one pillar of that order, the news media, has so far been left relatively untouched. The new government has taken the initial steps to open up some of the exclusive press clubs that dominate coverage at Tokyo’s powerful central ministries, but it has yet to follow through with more sweeping changes.

For a variety of reasons, cultural as well as economic, the digital revolution has yet to wreak the same havoc on the news media here that it has in the United States and most other advanced countries. The media landscape is still dominated by the same handful of behemoths that have held sway for decades, like the Yomiuri Shimbun, the world’s largest newspaper, with daily circulation of more than 10 million.

Personal blogs thrive in Japan, as do shopping sites and chat rooms appealing to groups from pet lovers to angry nationalists. But sites dedicated to news have found only a small foothold, and most of those are run by major news organizations, which often treat them as sideshows.

Most glaringly, there have been few of the alternative news blogs and news sites that have appeared in other countries, like The Huffington Post in the United States. The handful of sites that have drawn attention, like J-Cast News and The Journal, have failed to garner large numbers of readers.

Citizen journalism sites have earned the most attention here, largely for taking the lead in challenging media taboos and criticizing Japan’s press clubs. But they are far from prosperous. Before JanJan, a well-financed startup from South Korea, OhmyNews Japan, shut down two years ago and Tsukasa Net closed last November. Another, PJ News, has shrunk to a single editor who does not even have an office.

Takeuchi and others in the online media point to a number of reasons the sites have failed, beginning with advertising revenues that are too low to support even a skeleton newsroom staff.

But it also appears that Japan, with its cultural disdain for those who stick out from the crowd, may be inhospitable terrain for the reader-turned-reporter model, Takeuchi said.

Consider the contrast with neighboring South Korea. OhmyNews revolutionized the South Korean news media with reader-generated stories that challenged the big conservative newspapers, and in 2002 it helped elect a liberal president, Roh Moo-hyun. The site has become a powerful media player, with 62,700 readers-turned-reporters and two million page views a day, in a population a third the size of Japan’s 127 million.

But when OhmyNews took its winning formula to Japan, it flopped. Advertising revenues never materialized, the site drew a meager 400,000 pages views a day and just 4,800 readers signed up to write stories, said the site’s former editor, Masahiko Motoki.

Motoki and others say that another reason for Japan’s resistance to alternative sites is the relative absence of social and political divisions. In politically polarized South Korea, OhmyNews thrived by appealing to young, liberal readers.

"It is only when the society sees itself as having conflicting interests that it will seek out new viewpoints and information," said Toshinao Sasaki, the author of about two dozen books on the Internet in Japan.

Media experts say Japan has yet to see such critical questioning of its establishment press. They say most Japanese remain at least passively accepting of the nation’s big newspapers and television networks.

"Japanese are inundated with information, but they remain very naive media consumers," said Shin Mizukoshi, a professor of information studies at the University of Tokyo.

Still, there have been growing signs that Japan’s news industry may be primed for change. The biggest has been a slow but steady decline in newspaper readership, particularly among younger Japanese.

Circulation of The Asahi Shimbun, for example, Japan’s and the world’s second largest daily, has fallen by 3 percent over the past decade to just over eight million

When he started JanJan seven years ago, Takeuchi, 69, said he hoped to stir up Japan’s mainstream press and its top-down, uncritical coverage of the government.

JanJan, short for Japan Alternative News for Justice and New Culture, quickly drew praise for its critical stories on research whaling and other topics considered off limits by Japan’s mainstream news organizations. However, the site barely earned enough to pay for its operations. The death blow came from the global recession, as advertising revenues fell to $1 million last year from $3 million in 2007, Takeuchi said. He reopened the site in May as a much more limited blog.

Takeuchi said one of his biggest challenges was maintaining the quality of the site’s news content. Most of the articles submitted by readers tended to be rehashed versions of news stories from major media outlets, with the readers’ opinions added.

He also had difficulty hiring experienced journalists because most were reluctant to leave a big company for an unknown startup. Media experts said this might change, especially if big news companies begin to resort to layoffs or go bankrupt as they have in the United States.

"JanJan failed, but there will be others who try to do the same thing," said Mizukoshi. "JanJan has planted the seed."