Even though I have an account for years now, I just recently got hooked on HN. I still don't have an estimate on how much time I spend on it, but I don't even care. Ok, I use it as a news aggregator and I'll probably forget about most of it in a few days, weeks or whatever, but more importantly, I use it to find out about resources too.

Resources for learning and for my job in general, for my own products or for my day job. I think it currently might be one of best places to stay informed and on top of latest technologies.

I don't think HN and Facebook belong in the same category here, at least not for most of people. Somebody can still use Facebook to get informed about the technology, but most people don't.