Agreed. However, so long as advertising remains part of the mix, widespread deployment of ad-blocking software would undermine that, and therefore force a move towards alternative sources of revenue.Well, yes advertising is probably going to remain part of the mix .... i know places like the guardian go for a combination of adverts and donations. .... So a whole business model can't be ruled out on the basis of a couple of failures when there are successes out there too.
In some cases (maybe like the Guardian), there may be reasons (e.g. 'political') in addition to purely commercial ones for their existence, so it's not impossible that some of the sites would even be prepared to run at a financial loss if they had to.
Also, there will be a lot of variation between sites as to what their true marginal cost is. In the case of newspapers and other news media, they are primarily just making available via a website material which largely already exists in electronic form, so the infrastructure and human resources required may not be as great as one might think.
If I may ask (and if you're prepared to answer!), have you ever made a voluntary donation/contribution to a website and, if so, do you do it 'regularly'?
Kind Regards, John