Medium Day didn't really permit back-and-forth between speakers and writers, who could only submit questions on "paper." But allowing the questions to be asked can be valuable, because it will sometimes elicit and an oral answer the speaker hasn't and maybe wouldn't put in writing.

I've noticed that when I've been on panels or otherwise taken audience questions--say, after a talk at a bookstore--I'll make an offhand comment I haven't put in a story that to some people might be as valuable as anything I've written because it speaks to a particular need or interest of theirs.

But you're right that the format of a conference like Medium Day is a challenge to use effectively. You have to take a lot of chaff with the wheat that's helpful to you.