I've done it twice now, once at The Guardian and now at The Tate where it is in excess of 10,000 people.
It cuts through a lot of discussion, debate and prejudice. You get the voice of the audience at the Tate, for example, which is frequently under-represented, but incredibly helpful. You can pose questions on anything from policies to which poster should be run. It doesn't make the decision, but it informs it enormously.
You can ignore it, but if you do so, you know that you're ignoring it and proceeding anyway - which, equally, might be the right thing to do.
Different segments are represented in our panel, which are mainly about proximity to art: from someone who goes to the Tate once a year, another who is academic, right through, and they're represented statistically on that panel. So you can ask a question to different audiences or multiple audiences and cut it any way you like.