It also means that they would be more likely to buy other things from the paper than mere paywall access. If you get to know your readers and what they like, then you’ll know what they’d like to buy so you can sell it to them.
It’s certainly a nice idea, but I have my doubts newspapers could ever really pull it off. They were made for an entirely different purpose than social networking sites from the very beginning. You don’t go to a newspaper to keep up with what your friends are doing all day. But oddly enough, you can go to Facebook to read news—or at least, the news your friends find worthy of link sharing.
And prior to the Internet age, over centuries newspapers built an almost-entirely one-way culture. You read a newspaper to have them tell you stuff, and the only way you could respond was by sending a letter and hoping they felt it was worth publishing. That one-way nature is still a big chunk of newspapers’ DNA, and I think that seriously changing that is so far outside newspapers’ traditional specialty that many of them will have a hard time sorting it out.
But if any of them can manage it, the benefits pointed out by Ingram and the people he quotes could certainly make it easier for them to survive. They’re unquestionably worth trying for. The question is whether newspapers seriously will.