I'm 20 years old, I feel that's somehow relevant before I give my long list of anecdotes.
When I woke up this morning, I checked my feed, 3 notifications! The first (ranked by importance of course) was that one of my cousins was pregnant. She lives in Spain, I'm the only member of my family in the UK, how would I otherwise have found out? Snail mail? Pah! Takes too long and my address isn't always static for longer than a few months. Phone? Really? Do you know how much international calls cost when you aren't on a Silly Valley wage?! E-Mail? ... Do people actually still do the whole E-Mail thing? And isn't E-Mail completely broken anyway?
The second was a party event my friend was throwing and had invited me too this weekend, it took one click and now I know all about it, I accepted and left a message.
So in 30 seconds on one application, I've discovered my cousin is going to have a baby, congratulated her and let her know that I "like" this outcome, told my friend I'm cool to hang out this weekend and asked him if he wants to go halves on a Pizza Saturday.
Last night I used it to talk over video with my grandma who's been ill recently (and also coincidentally lives abroad) because she doesn't know what a Skoop (Skype) is and MSN no longer exists, but Facebook is still here, she's already on it and she uses it frequently.
After this I checked up on my company feed to look at photos of my co-workers birthday party and the comments on the photo I took (and uploaded in seconds to the internet after applying filters to make him prettier) of him opening his presents.
I literally just got out of bed and I have a message already from my girlfriend (who's out of texts) asking me what we're doing tonight, I've told her it's a surprise and send her a photo to give her a clue.
Anyway...
The point of this is that while you may detest Facebook for whatever privacy issues you may have (and lets face it, other companies such as our beloved Google are often much, much worse) it is a fantastic application making it easier than ever to connect to the people who I actually care about (for the record, I only keep 40 friends on there), if perhaps a little out of your particular use case.