I was invited to take part in one recently - I'm a little annoyed, in fact. I completed an online questionnaire and it informed me that I was selected - it even gave me two timeslots during which I'd participate in a 90 minute teleconference.

Then, two days before the teleconference, I get an email that I was "waitlisted". It just seemed disrespectful and sloppy.

I believe part of the issue is that it was being co-coordinated with Visa. The content of the survey was more about the Visa Signature card than it was hotels. So I don't blame this one on Marriott Voice...but somewhere in the marketing department of Marriott or Visa, they have contracted with a third-party that doesn't seem to be able to organize these things well.