Buy and sell your friends?

I've become quite used to the big variety of stories and feeds that keep popping up on facebook. But one story that I saw today made my eyes open really wide:

The app seems quite harmless in itself: all it seems to suggest is that you treat your friends as pets.
From the application's web page:

Buy and sell your friends as pets! You can make your pets poke, send gifts, or just show off for you. Make money as a shrewd pets investor or as a hot commodity! Friends for Sale is the bees knees!

But they might want to rethink their newsfeed stories