This poll made me think of what the auction channel is, and what it could become, should it need to change. The way I see it, a localized auction channel the way it is now has very limited use. In general people prefer to advertise their marketing activities in gossip. And for those who would still want a channel with shout reach, just shouting would fulfill the same purpose, and in a manner that is a lot more IC than using a separate channel.
With that in view, I believe auction's reach should be made global but kept separate from gossip. Gossip often hosts diverse discussions, more often than not unrelated to the game. The auction channel will help keep marketing announcements separate and more prominent. This will serve both OOC purposes and IC purposes best in my view: IC it could be made to look like a flood of groffels roaming the streets, leaving notes at every doorstep and approaching every passer-by.