WITHIN five years internet users will have to pay to access content now free, according to Barry Diller, chief executive of InterActiveCorp in the United States, which runs about 30 websites and turns over $US1.5 billion ($A1.8 billion) each year.

"I absolutely believe the internet is passing from its free days into a paid system," he told the Advertising 2.0 conference in New York this week.

Mr Diller said the paid model would include subscriptions, one-time purchases for access to sites and micro-payments.

But not all agree. "That's quite a prediction," said Neil Ackland, managing director of the Sound Alliance Group, the largest independent online publisher in Australia. Its niche music and lifestyle sites — such as FasterLouder, SameSame and Mess+Noise — attract 500,000 unique hits a month.

"We've been doing that for more than 10 years and manage to make a profit out of advertising as our model — why would we want to change that?"

Mr Ackland said people would be willing to pay for some content "but I think people are already paying for that content: finance, investment, dating, real estate information, high-end information. People already recognise that value.

"But a news story that is on 600 websites around the world simultaneously doesn't have any value to the end user. It doesn't have any exclusive value they can't get elsewhere."

Andrew Sims, general manager of marketing and products for Melbourne-based internet service provider iPrimus agrees: "If one of the big newspapers today wanted to make everyone pay for content, people would go elsewhere … there'll be another two, three maybe five sites out there that'll provide the services (free)."

The demise of respect for copyright on the internet plays a role. Canny consumers can find their way around information toll booths; once someone has access to content they can put it out there for others to access.

"We see that with all types of things," said Mr Sims, "(such as) illegal downloads of video content and music."

Companies must learn to survive on revenue via advertising on their sites, he said.

"Advertising companies are moving away from traditional media — print and TV — and putting their money online because they feel they get better bang for their buck. As that trend continues you'll see more and more people spending online, which will certainly help websites whose ultimate goal is to deliver quality content."

The shift in how young people, especially, found information was also a factor, said Mr Ackland.

"A lot of people now already get a lot of their news and information from forums and blogs — when they happen to stumble across news that's been posted in forum threads …

"Twenty years ago there was a limited number of places where information could get published and distributed. Now there's an infinite number … The idea of putting information behind a walled garden? I just don't see it happening."