> Maybe sites like Stack Overflow have 0 variable cost but this is more of an exception.
Interesting, how so? I find it difficult to imagine any media site that, once they produced a piece of content, has to pay any other substantial cost as they get more views.
In other words: doubling up page views for the Guardian does not mean doubling up the costs of producing the articles. That's what I mean by "substantially zero variable cost".
The viable model is paywalls and that's where quality content will go. I don't see a big deal with that as I will gladly pay for content that I value.