My feeling on it has always been this. If one person gets up early in the evening and says "Thank you so much. You're a huge influence on my life. blah, blah, blah" and the audience then applauds. To me, that means that person has spoken for the audience. It's out there. It's been stated. It's been ratified and we can get onto the questions.
Personally, the best one of these I've been to was the one on Long Island two years ago, with Dave, Fran, Kevin, Jane and Karen Falk. for those who weren't there, the lined everyone up outside before the panel and gave everyone an index card and a tiny pencil (like the ones used to keep score at mini-golf) and everyone wrote down a question. The staff collected the questions up and while everyone was filing into the theater, Craig Shemin was sorting out which questions were useable and which ones were "Has there ever been a study to see what the world would be like if Jim Henson had played Bert instead of Ernie". Consequently the question were more thought out and it made for a more informative and entertaining afternoon instead of watching the performers wait very patiently through someone's life story only to get to some head-scratching "was that even a question?" moment.
sorry, this has actually been bothering me for a while now.