Your social graph should / could be a personal filter for finding good content. Providing serendipity.
Almost sounds like whenever I found a book I like, I would also read the books mentioned in it, like tracing his information source; And if I really like the author, I would go even further to learn about his family or what people he hangout with, haha, but I'm not so sure social media could work like that? and from my experience, many good stuff is usually hidden, you really need to do the work to dig.
"It's not information overload, it's filter failure" - Clay Shirky
yes, we have abundant information everywhere, but the good ones are almost drowning in the ocean of noise.
Good article!