As we see scores of amateur authors invest enormous amounts of time and effort to build audiences through social media, perhaps we’ll see more successful authors withdraw from these activities completely. Chuck Palahniuk and Jeffrey Eugenides come to mind as examples of authors who are not nearly as reclusive as J.D. Salinger or elusive as Thomas Pynchon, but do strategically avoid overexposure.
I can imagine a future in which participation in or abstinence from social media becomes a generally agreed-upon marker of stature and cultural value. In a world where constant media exposure is almost obligatory, mannered obscurity might be the only way to really get noticed.
The question, of course, is whether these authors will need to use social media and similar platforms to become name brands in the first place. Maybe these media will be a tool exclusively for early-career or undiscovered authors, and once established, the online presence will gradually wither, then disappear entirely.