Pre-internet and social media, “supermarket tabloids” were the fake news of the realm. I did some digging… in 2002, which still predates people predominantly relying on Internet sources for news and certainly predates social media, the king of the “supermarket tabloids,” The National Enquirer, sold 88% of their issues as “single copy” versus subscription. It was also held the seventh highest circulation revenue of all magazines, trouncing “real news” publications like Newsweek and U.S. News and World Report.
What this tells me is that people didn’t consciously decide to “eat” a steady diet of “fake news,” but that they would “react” to something they saw on the cover and decide to consume the information. This behavior is very similar to the dynamic regarding “fake news” distributed via social networks. I agree with Nick that the more Facebook tries to control this phenomena, which isn’t a new thing, the more it’s likely going to hurt their subscriber count.