With the typical hype-machine that is Comic-Con, I'd like to point your attention to this probably-under-seen piece that Rob Salkowitz wrote just as the convention was about to get underway. It revolves around some findings Eventbrite uncovered in surveys they conducted with people who were buying convention tickets through them. If you've been paying attention the last few years, there shouldn't be anything terribly surprising. But, as I've gleaned from some creators, there are those in the industry who simply can't see what's going on in front of their own eyes!
The short version is: fandom is about community, which conventions facilitate. (Of note is that convention populations are getting closer and closer to reaching gender parity, and have done so among those attendees under 30.) But they also provide a good opportunity for commerce. People go to shows to meet up with people in person, and to spend money on stuff (presumably items they have limited access to elsewhere).
Also noteworthy is this statistic that was being presented at Diamond's booth in San Diego. (The photo is care of @CharlieChu, but I can't vouch for the data's origins and/or authenticity.)
I was at the small Mania Comic Convention a couple weeks back, and one thing I noticed was that the longest line for pretty much the entire time I was there was for the lady doing face-painting. Next was probably for getting pictures with the cosplayers. Now, granted, a good chunk of the audience there were children and their parents, so the demographic is definitely skewed from something like a Comic-Con Internationa, but the same principle is in effect. The kids were getting the most of out of the show when they had a personal interaction: getting a photo with a superhero, or getting made up to look like one.
Now if you're a dealer or tabling at an Artists Alley, what can you do to encourage that personal interaction? Some of the larger publishers have the "easier" time of it by spending a lot of money on large displays. This makes for easy-to-spot meet-up locations where "under the hanging Marvel logo" is easier to note and visually identify from the floor than "booth #3471". But can you do something eye-catching at a smaller scale for Artists Alley?
The classic "interaction" item at shows, of course, is creator signatures. But what about devoting a portion of your booth to a photo op? How many people stop by to get their picture taken with their head sticking out of the custom-built TARDIS? Or in front of the really cool display that makes you look like you're in a starship? Has anyone tried using a simple green cloth background to let people do their own Photoshopping over your greenscreen?
It's pretty obvious that you need to be aware of what people are responding to specifically with you and your wares at a convention. But by also paying attention to the larger information sets from con-goers at large, you might also be able to draw more people to your booth and help make the show more successful for you!