"Some good points, Sean. I didn't mention it in my article, but during the Q&A at SMX one of the Denny's reps mentioned that the increasing amount of social activities, especially among younger people, that take place on private or anonymous networks is indeed a challenge. He noted that it is still a very small part of their landscape, but is growing. The question will be whether teens will retain their same privacy concerns as they grow older. Sure 60% of teens on Facebook may have private accounts now, but that's understandable as they want to keep their activities hidden from parents and predators. But once they grow up and have families, will they become more public?" - Mark Traphagen