Other than the aggregation engine that is the Huffington Post few online only sites have managed to achieve mass market success and now Slate, one of the oldest online only magazines, has swung the axe and cut some of its most high profile staff.

Coming on the day when yet another newspaper announced it was putting up a paywall, this time the Newsquest-owned Herald in Scotland, is that another nail in the coffin of free web content?

Slate, owned by the Washington Post Company which bought it from Microsoft,  cut a number of key staff including its media critic, Jack Shafer, who is one of it best-known writers.

The WSJ reports that the cuts come weeks after the Washington Post bucked the trend and reported that ad revenue at its online publishing operations was down by 13% in the second quarter. Most others are still seeing online ad growth.

Last year the Washington Post sold Newsweek to 91-year-old billionaire Sidney Harman. The title was then merged with the Tina Brown helmed Huffington Post rival the Daily Beast. Another Slate competitor.

Slate says the cuts are unrelated to the fall in advertising and its general manager, John Alderman, argues the site can still support itself as a free website.

“Along with Salon.com, Slate was a pioneer in online news. Launched around the same time, both mixed high-brow political, business and cultural commentary with the sort of reporting that has long been the province of print. They have experimented with charging for content and have altered their topic mix to try to find the right economic model. But both have struggled to attract adequate ad dollars without the print companion that subsidizes successful news sites like Politico.

Unlike Salon, which has had significant budget and staff cuts in recent years, Slate has maintained higher cost-per-page view rates than many of its competitors, industry executives say. The site has also flouted industry axioms with initiatives like a program that requires writers to take four to six weeks off to work on a long-form project,” the WSJ reports.

But with budget cuts and rivals like the Daily Beast and the Huffington Post fighting for the same ad dollars you have to wonder whether there is any future for sites like Slate?

Much bigger websites like The New York Times have already made the jump to a metered paywall with many others looking at it.

In the UK the Telegraph and the Daily Mirror are both considering paywalls and yesterday the Herald in Scotland announced it was moving towards one:

“We’ve created this new section as the Scottish media industry faces the hardest financial time of a centuries-old history amid the digital revolution.

“Newsquest, which owns HeraldScotland, has announced that later this year it plans to introduce a metered subscription charge for users to get full online access.

“More details will be made public soon, but we want to hear your opinions, so read the articles here and use the Comment box to share your views.”

However, I don’t think that paywall approach will work for all. There is only so much people will be willing to pay for. So does that spell an end for sites like Slate which can’t make free content work and probably won’t be able to make the jump to paid for content?