Paying for content is pretty much idiotic. You want your content to spread, it costs zero to spread, and so hanging some ads around it is by far the most effective way to monetize.
Relying on ad revenue is exactly how buzzfeed got into this mess.
What mess? The article confirmed that it's pretty much a non-issue. Only 3 out of more than 1,000 removals had anything to do with advertisers and at least 2 of those 3 were legitimate take-downs and probably the 3rd one, too.