"In the end, you know, it's not so much about the money itself as the dignity it confers."

With those words, written in an email exchange with a senior editor at the Huffington Post, the career of Mayhill Fowler, "citizen journalist," officially ended.

She was once a trailblazer for a new model of doing journalism. But her very public departure in late September 2010 from her most prominent outlet raises questions about whether any model that relies on unpaid labour is ultimately sustainable.

You may not recognize Mayhill Fowler's name, but you might recall the two big stories she broke during the 2008 American presidential campaign.

Blogger and reporter Mayhill Fowler. (Courtesy Mayhill Fowler)

It was Fowler who wrote about former president Bill Clinton referring to a writer for Vanity Fair as a "scumbag."

And it was Fowler who wrote the story of then candidate Barack Obama telling guests at a California fundraiser that people in small-town Pennsylvania "cling to guns or religion" because they are "bitter" about their economic status.

Dubbed "bittergate" by the U.S. media, Obama's statement nearly derailed his nomination and is still trotted out by his political opponents.

Fowler wrote these stories for the Huffington Post, the popular American internet "newspaper" where she was part of a bold experiment called Off the Bus.

The idea was to enlist thousands of citizen journalists across the U.S. who would report on how the campaign of 2008 was unfolding in their communities.

More than 12,000 people eventually signed on, including 1,700 writers.

They were the unpaid amateurs and, because of them, Off the Bus was able to operate for 16 months on a total budget of just $250,000.

Three paid staffers at the Huffington Post organized the contributors and edited their material.

The collaboration would, its founders hoped, bring a new dimension to political reporting, one that focused less on the horse-race aspect of who is ahead and more on the issues that people actually cared about.

Their slogan was "campaign coverage by the people who aren't in the club."

Mostly off the bus

These citizen reporters did some interesting work during the long presidential campaign, but this experiment in pro-am journalism likely would have remained well under the radar were it not for Mayhill Fowler and the two national stories she broke.

An unlikely journalistic hero, Fowler was then a 61-year-old Californian, a former teacher, aspiring fiction writer and a supporter of Barack Obama. She had never done any political writing before.

But she had two things that most citizen journalists lacked — time and money. Rather than confine her reporting to her home base in northern California, she decided to travel the country and report the campaign from a perspective that she described as "the middle distance."

She would be closer than the stay-at-home bloggers, but farther back than the established media, whose coziness with the campaign advisers disturbed her.

Still, both her big scoops raised significant ethical questions and Mayhill Fowler became a lightning rod for people who were uncomfortable with the whole idea of citizen journalism.

For example, she did not identify herself as an Off the Bus correspondent when she questioned Bill Clinton about the Vanity Fair writer. (This provoked howls of outrage from the journalistic establishment.)

And the Obama fundraiser in San Francisco was actually closed to reporters.

Fowler was there because she had contributed money to his campaign, something no mainstream media outlet would allow its reporters to do.

Cult of the amateur

But do citizen journalists have to play by the same rules as mainstream journalists?

Andrew Keen, author of The Cult of the Amateur, thinks they do.

When I asked him about Mayhill Fowler, he described her as someone who "epitomized amateurism" and exposed "the bankruptcy of the Off the Bus model."

But she had many supporters as well. When I met her in June 2008 at the Personal Democracy Forum in New York City, she was the poster girl for all that was right about citizen journalism and the critical role it could play in revitalizing democracy.

Fowler was a bit overwhelmed by all the plaudits that were coming her way at the forum, and still reeling from the drubbing she had taken at the hands of media critics and Obama supporters.

She simply thought there were stories that needed to be told and was grateful to have had the opportunity.

She had spent thousands of dollars of her own money travelling the country, but had no complaints about that. She was happy that Off the Bus had agreed to cover her expenses for the latter part of the campaign, though it still wouldn't pay her for her reporting.

At that point, all she felt was that "there is a place for citizen journalists out there because mainstream media isn't getting the whole story."

'I've paid my dues'

After the campaign, Fowler started a blog, wrote a book about her experience and continued to file political stories for the Huffington Post.

Blogger and website operator Arianna Huffington accepts the Best Politics and Best Political Blog award at the 13th annual Webby Awards in June 2009 in New York. (Jason DeCrow/Associated Press)

The site has become one of the most popular news destinations on the web and now turns a tidy profit. But the vast majority of its content is still delivered by an army of about 6,000 unpaid bloggers, like Mayhill Fowler.

The company policy is that it will not pay writers for opinion. But Fowler insists that what she does is reporting and sees no distinction between what she writes for free and what the three paid reporters on staff do for their money.

In her email exchange with Huffington Post editor Roy Sekoff, Fowler wrote, "I've paid my dues in the citizen-journalism department; I'm a journalist now." But Sekoff was unmoved.

"We completely understand and wish you all the best," he replied.

"Let this be a warning to you, citizen-journalism enthusiasts," Fowler responded on her blog. "In the end, what you are doing is enhancing somebody else's bottom line."

Most of her readers supported her decision, but some wondered what took her so long. "Did you ever stop to think that your free work undermined the wages of professional journalists, or did that just occur to you?" asked one commenter.

In her blog post, Fowler described Huffington Post co-founder Arianna Huffington as the "quintessential opportunist.

"As I thought I was proving myself to her to be worthy of journalism, she on her part was milking me for everything she could before letting me go."

The Huffington Post is currently one of the most successful of the new business models for news currently being worked out on the web and boasts revenues of about $30 million a year.

But can a business model that relies on the few profiting from the unpaid labour of the many ultimately be sustainable? The story of the rise and fall of America's most celebrated citizen journalist suggests the answer may be no.