But other social networks have actually lost users over time, even though supposedly a network becomes more sticky as more of your friends join it. I'm finding Facebook more off-putting, not more useful, as Facebook keeps trying to invent ways to draw me into the site. I spend way more time on HN than I spend on Facebook, because I find smarter discussion on HN.
I think of this as the acquaintance paradox. Social networking sites are best at keeping you in touch with your acquaintances (after all, your close friends already know where to find you and what you are doing). But someone who I am already acquainted with and who is not a close friend is merely an acquaintance for a reason - I don't click with them, I don't have time for them, whatever.
The paradox is that I am therefore more likely to find a stranger interesting than an acquaintance, especially a self-selected group of strangers. I think that is why you prefer HN to your facebook buddies.
