It's not like you get to pull a name out of thin air and message it for a dollar, it tells you things about people you can't normally reach (IE normally have you blocked from sending messages), and lets you decide if you want to reach them anyway, despite the fact that you are normally blocked/put into other.
The wonderful spin they put on this is: "For the receiver, this test allows them to hear from people who have an important message to send them."
That important message could be "i'm stalking you, bitch", being sent from a throwaway facebook account. As the article points out it also allows you to send messages to people you aren't friends with, so you don't even have to have gotten them to friend you. Normally it would have gone into other and you'd likely never have looked.