Facebook and youtube/hulu/pirated TV shows are worlds apart to me. Facebook is something you actively take part in, you contribute to. This has almost nothing in common with the passive entertainment of TV that people enjoy. I didn't cancel my cable connection because facebook, AIM, or any other social connecting mechanism came around; it's because I found I could spend my passive hours (read: not typing things) on a computer instead of a TV.
It has nothing to do with the nature of the activity. Graham's point is that the social networks provided the last stimulus needed (over the last 30 years) to get computers into daily use in almost every household in the first world.
You didn't cancel your cable, but you likely spent more time in front of the computer after picking up AIM and FB than before. This signal indicates the front edge of a trend. This is visionary stuff, not hindsight.
