How to show a message to returning visitors?

Hello,

I want to show a message on my website asking users for feedback, but I only want it to be shown to returning users. It would be even better if I could show it only to people who have come to my site at least say 5 times.

I have Google Analytics installed, and I can see it tracks user loyalty, so maybe is there a way to use Analytics variables to check whether a user is frequent or not?

I'd start with looking at _pageTracker methods named _setCustomVar and _getVisitorCustomVar.