Fuzzy bird farming
Maybe we should hurry and buy some Zynga or Rovio stock. I'm sure they have detailed data on pretty much anyone on the planet by now.
They both kinda helped. So some of Zynga's apps locked features behind having x friends. From memory, extra pixel crack was awarded for having 500 or 1000 friends connected. So people promptly created their own ways to bulk add 'friends', who weren't friends in the conventional sense. That was useful for polluting your friends list, and confusing social network analysis attempts.