An influential technology expert has suggested that Facebook and Google should consider overhauling their business models.
Jaron Lanier - who is sometimes referred to as a father of virtual reality - has suggested that the giant American firms should look into the prospect of allowing users to pay for their services, rather than just generating revenue through adverts.
Speaking at an event in Vancouver, he insisted: "These companies need to change."
However, Facebook boss Mark Zuckerberg recently played down the prospect of this happening.
The billionaire explained that the idea went against his firm's stated ambition.
He said: "A number of people suggest that we should offer a version where people can not have ads if they pay a monthly subscription, and certainly we consider ideas like that.
"But overall, I think that the ads experience is going to be the best one. I think in general, people like not having to pay for a service. A lot of people can't afford to pay for a service around the world."
Meanwhile, Lanier suggested that the approach of some tech companies has become outdated.
He explained: "We made a very particular mistake in the 90s when early digital culture had this lefty, socialist mission, which meant that everything on the internet must be available for free."
And this attitude meant that companies like Google have become reliant on advertising, according to the expert.
Lanier said: "In the beginning it was cute but as computers became more efficient and algorithms got better, it can no longer be called advertising any more - it has turned into behaviour modification."