More Questions About Facebook

So, I am in my early 30's.. for some, it is "too old" for Facebook - and some of the criticism about the social networking site is that is has become a 'youngens' site. Most people who I know who teach mentioned that most of their "friends" have been their students...

Today, I had my first "friend" invite from a student for a class that I TA'd. I was not quite sure how to handle this. My daughter tried to explain to me that it's all about having as many 'friends' as possible. I asked her why, but she couldn't really articulate it, instead opting for the "just to show how cool you are" cop out (she admits that it's a cop out since she has no 'real' answer "it's just the way it is mom"...).

So, what is Facebook for? For who? I thought it was a way to keep in touch with people that weren't on my messenger. Or for people that I can't quite muster up an entire email - but still want to know what they have been up to. I admit, I have enjoyed getting messages from old friends from high school, but once the "oh my god - its been so long" has worn off - why am I on Facebook? And what do I do with an invitation from someone who I only know throw a class list?