It's one of those strange "networking things" that people like us just can't understand.
Not really.
I just use it to make it easier to accept invitations to events and such. Then there's the occasional person to stalk. Pictures to check out. Ect.
If people you've never met are adding you because you go to their school, there's several explanations. They're either trying to be polite or using the fact that you share the same school as an excuse to increase their friend count, and therefore, their popularity rating.
