There is no normal number of visitors and nobody has tracked any of this.
And it would be a bit of a moot point even if they had been tracking non-attendee visitors in previous years since the point in all of this is to pay for advertising to
increase the number of visitors. Whatever the counts were in prior years, the AAW obviously feels like they were too low. In this, I agree with them. The more non-attendees we get through the door, the better. Almost everyone, even locals, who are paying between $325-$360 to attend the full symposium are already woodturners or are already deeply interested in becoming one. These people do not fully represent a growth opportunity for woodturning as they are already in the fold, more or less.
So how do we get more of the rest of the world into the event to check it out and, hopefully, develop an interest in woodturning? Advertising. I'm sure some people might just be wandering by the convention center that day, see the signs, and think, "hmm, that's look interesting, let's check that out", but those numbers will be low. A few well-placed billboards or local newspaper ads could do wonders to introduce the hobby to hundreds or thousands of new people.
The question is: will they be turned off when they get to the door (or see the print on the ad) and fine out that it costs $10? One person probably won't be, but another person with their entire family in tow may very well be. It would be better if it is free, and keeping it free for all also generates a subtle but important undercurrent of accessibility and good will towards those very people that the AAW (and the rest of us as dues-paying members) want to expose to the hobby that we all know and love. So how many will be turned off? No one knows, but I think it is safe to say that the answer will definitely be "some".
I have seen mentioned elsewhere that the gallery will remain free but that the entrance fee is only for the vendor's area. I don't personally think this is good enough. Both offer an "ooh! aah!" experience that is different from one another.
So, again, advertising is a good thing but obviously someone has to pay for it. Personally, I think it should be paid for by slightly increasing the price of symposium attendance.