Hi
Yes I use it and it does work. I have been contacted mainly cause, if I look at a bank and they want to know my credit they will inquire and the credit analysis will notify me of that, or any activity for that matter.
I think it's like 10 bucks a month which automatically goes on my American Express every month. If you want to cancel you just call them and they will do it.
It's a little added protection and I feel it's worth it.
Good Luck