Socially inept

OK, it's come to this. I desperately need someone to explain to me exactly what the deal is with social networking sites?

I don't regard myself as an utter Luddite. Although admittedly not necessarily one of life's early adopters (I don't have an iPod, an iPhone or a Blackberry, Raspberry, Strawberry or any other form of soft fruit for instance), I do get technology and it's benefits -more or less anyway.

I also get the point of blogging - a chance to show off and inflict my opinions on anyone daft enough to read them - and I'm on LinkedIn as a way of staying in touch with business contacts and former work colleagues.

I have to admit, however, that the point of Facebook totally escapes me. I do have a Facebook page (is that even the right word?) but not a clue what to do with it. Keep friends up to date with my scintillating life? Promote my blog? Honestly, I'm not taking the piss here - if anyone can tell me what Facebook is for I'd be delighted to know.

As for Twitter - what the hell's all that about? Again, I have a Twitter account and occasionally remember to let people know that I've updated my blog, but that's all. Those that are interested would, I figure, stop by the blog anyway from time to time. Those that aren't interested simply aren't interested - and I'm damned sure that they've no interest whatsoever in what I've just had for tea. I have also seen blogs which feature Twitter updates - usually updates on the latest entries on the blog. So you let people know on Twitter that you've updated your blog and on your blog you feature your latest Twitter entry ("tweet?") to say you've updated your blog...? Is that right? There must be a reason so, again, if anyone can explain the how, why and wherefore, I'm all ears.

These sites are hugely successful so there must be something I'm missing but, with my hand on my heart, I just don't get it.

Answers on the back of a postcard please ...