[camikazeg]

It seems that a simple solution would be to cut out the ad networks. If the New York Times or The Economist just serve the ads themselves, rather than using a third party network wouldn't the ad blockers be unable to distinguish them from other content?

Sure they lose targeting, but physical media has existed for years based on ad revenue from companies that paid them directly for advertising. Even the tiniest local and university newspapers have gotten by with free distribution and paid ads for as long as I can remember.