Hey you're lucky! I never got the chance to fill out a survey from them ever in my life, maybe I'm just a Silver?
I don't how they pick the people to do the survey. But I just know that they have written names on the survey and they hand them out to those specific people.
They seem to do that from a list. I filled out survey many times when I was SL and GO. I have not been asked as much since I was DM. In fact, the last time I was asked to do that was probably a year ago (or more). They handed out a pen with each survey. The last pen I got was a kind of .... so so.