Social networks

I've just realised that my behaviour pattern in social network looks that way:

1. Register
2. Give up on it: don't use, don't talk with people, don't add anybody, etc
3. Some people start adding me, I add them back (why not?). This step repeats several times.
4. When I have a plenty of people 'friended'/'connected' whatever, I realise it makes no sense as I don't really talk to anybody so...
5. I delete the account.

I guess the only interesting social network was livejournal as in state it was few years ago, because it was interesting to know what's going with people you know (but not close enough) or interesting people you don't know. But for some reason, people don't write much interesting stuff to their journals on livejournal, just post some bullshit.