People have always been happy to pay for newspaper and magazine subscriptions, as long as the words arrived printed on actual paper. Asking those same people to buy that same content in digital form is another story.
A few outlets have had success with paywalls on the majority of their content, but it’s hardly the norm. Now that tablet usage is increasing, digital magazine subscriptions are on the rise, but still, they usually come as a bonus when you get the printed matter in the mail.
Oddly, people are much more likely to purchase ebooks. In the UK, Amazon now sells more ebooks than print books, so why aren’t people buying short articles online?