I tried it with Amy Winehouse and it got it but it was an easy one. I tried it with one from the business world (my CEO) which I thought it would never get and it did. I was a bit amazed, I must admit.
It's pretty impressive and got the first two I thought of. Then I tried Peter Crouch as well and it got him in 19 tries, despite me not knowing the answer to 3 or 3 questions.