The word "friend" has been so cheapened in this modern age. Even more so with Facebook and other similar sites.
A friend is someone you go hunting with. Someone you go fishing and camping with. Someone you spend time with (outside of work and offline). Someone you go to the park with, etc. I suppose you can develop a long-distance relationship (not necessarily romantic), but it won't realize it's full potential until you actually meet in person.
You will most likely have only a few friends in your life. You will have many acquaintances. Most of the "friends" on Facebook fall into that second category. Nothing wrong with that, that's just the way it is.
I suppose an "acquaintance" request just doesn't sound as social.

neil.postlethwaite@... is correct.
The very premise of this article makes no sense to me. Say you are my "friend" on Facebook. That means you have more "friends" than I. I am also your "friend" on Facebook. That means I have more "friends' than you. Sounds like that "Grandfather Paradox" time travel stories like to mention.
By the way, I dumped my Facebook account a couple of years ago and have not regretted it.