Something shocking has happened to US journalism: it has parted company with the free market. Perhaps the divorce is irrevocable, although a state of denial still exists. This has been a gradual process but the events of the past few months make the rift visible, though still largely unacknowledged.

Five months ago the Guardian pushed the button on the largest scoop in US news since Watergate, Edward Snowden's leak of confidential NSA files. This demonstrated that the biggest stories will no longer automatically go to the most established (US) newsrooms. Glenn Greenwald, who attracted the leak and led the story, was unorthodox in having a more opinionated and adversarial approach than traditional "print" journalism in America, and the Guardian is unorthodox for US news in having a heavily cross-subsidised model – or loss-making as some critics would have it (disclosure, I am not an unbiased observer).

In a narrative arc demanding dramatisation, Greenwald announced two weeks ago he was leaving the Guardian to set up an as-yet-undefined journalism venture funded by eBay founder and democracy activist Pierre Omidyar. And in a postscript as unlikely as Middle East peace, Bill Keller and Greenwald exchanged views on the new model journalism in the New York Times, which Keller used to edit.

With the pair agreeing to disagree about "objectivity" versus "activism", it was a civil, compelling exchange about the changes in the process and identity of what it means to be a journalist. It did, however, leave out the important historic framing for "objectivity" in the US press: a concept formed when most city newspapers dominated a market and did not want to alienate half their audience. Once this model broke, everything else was up for negotiation. A new model that is explicit about priorities other than profit will mean new types of journalism in every respect, both for good and bad, and Greenwald, Keller, Omidyar and the rest of us are all in it together.

The Guardian represents but one of a set of interventions in the US that create an irrational market for journalism. Over the past six months this has become transparent: the Boston Globe, bought 12 years ago for $1bn by the New York Times, was shed for $70m; Washington Post proprietor Don Graham sold it for $250m to Amazon founder Jeff Bezos; al-Jazeera America launched, funded by the Qatari royal family; and finally Omidyar brings $250m of new investment from which he has demanded no immediate return.

In a few years the non-profit news sector has gone from being seen as a temporary embarrassment for US news to a cornerstone, with dozens of organisations adopting a funding model reliant on diverse revenues. ProPublica, the Pulitzer-winning investigative unit, has had considerable impact, ditto the Texas Tribune. A Knight Foundation report on non-profit news last week saw fragility in the sustainability of the non-profit model but noted its growing significance.

The involvement of smart technologists such as Bezos and Omidyar is creating a less predictable world for market-driven journalism; costs are no longer tied to the ebb and flow of market revenue. There is nothing new in government, venture capital or rich donors funding news, but for a US industry that has always seen profitability as the root of good journalism, it is an important moment.

• Emily Bell is director of the Tow Center for Digital Journalism at Columbia University, and a non-executive director of the Scott Trust, owners of the Guardian and Guardian Media Group