Well, it's a good question, and I am glad you asked that. Did everyone else hear his question? He asked the intricacies of panels and why random people would want to hear other random people talk. [deep breath] Let's look at the first slide, where I explain this based on a study of 1000 random people at GenCon in 2005... jk :)
[feel free to smack me]
I can't speak for all conventions, but I have run panels for EveCon, CastleCon, HalloweenCon, CthulhuCon, Balticon, GenCon, Worldcon (BucConeer 98), Katsucon, and smaller cons time has erased from my memory. The panel topics have varied greatly. Some are silly, and some are dead serious. Some people come to see me, or the group I am with. Some have been workshops, some have been readings, a few signings, but the majority have been me and a bunch of other people discussing some subject we have a presumed authority of. I say "presumed," because it's true, some of us are put on panels by the programming department that makes us wonder what the hell they were thinking. "Why am I on in the 'Masturbation in Erotic Sci Fi' again? Right... because I wrote a book... and the head of programming is playing a joke on me. Ha ha,
daecabhir, very funny."
But most of it is topics I know. As a writer for MSD, they have me do panels for conventions based on designing campaigns and characters. Who am I to tell them how to do this? Who is anyone? I am an average Joe who figured this stuff out. Some people need ideas, or come with half an idea, or benefit from another's experience, and I also do a lot of Q&A with them.
For people running conventions, it's filler sometimes, sure, but I have hosted panels that have packed the walls. I had one on "Why Do We Hate Barney" at one con that got people so riled up, if someone dressed as Barney the Dinosaur walked past the door, they would have been torn apart like a pack of zombies over a corpse.
Does this answer your questions? Good. How about the guy with his hand up in the back?
[I keed, I keed]