How Do You Avoid The Awkwardness...

Just ignore the dumb comments about your game (it may be hard I know ;).

If you really want someone to leave your stand, whether they have Asperger's or are just socially awkward, it usually best to be polite, but direct. So, I would avoid saying something like "Have you already seen game X or Y?", because they might not pick up on the clue that you want them to leave. They might just respond and say something like: "Yeah I have seen game X" and then not leave or even worse, go on about game everything that is wrong with game X ;) I would say something like: "Hey man, thanks for visiting my stand, but since you do not seem intent on buying anything, could you please move on and make room for other interested customers. Again thanks, and have a nice day!".

This post is totally awesome.

I've never run into this problem at the level you're mentioning, but after attending multiple conventions, I know what corners and crevices to steer clear of. My convention time is part playtesting, part work, and part play, and I certainly don't want to waste any of that important gaming time on a situation like you so odoriferously limned.

Check out Unpub.net. Clean convention, good non-gamer/gamer/playtester traffic with free admission for the general public. (PLUG)

My first year at Origins, I took a deep breath and broke out my game for a playtest with 6 strangers. The game lasted about 90 minutes, the scores were close, and the people playing, while a bit timid and awkward, seemed to be engaged the entire time. Afterwards, they nodded their heads, and with a slight grunt, they all simply got up and left. I think the one girl said, "let's check out the exhibitor's hall now." I was completely miffed, broken, while sitting at an empty table.

The next day, I played the game with another group and signed a publishing contract.

I still remember the feeling though. Everything goes so well, and then, silence. Eeeeery silence. (Luckily, the story doesn't end there. Later that year, at World Board Gaming Championships, one of the playtesters from that game walked up to me and said, "Hey, I really liked your game. Did you get anyone to publish it?" I felt my shoulders go all gooey; a weight had been lifted. Later, when the game was on Kickstarter, I noticed him as one of the early backers.)

So, I've learned to let anyone play. If they seem like they'll be a problem, I use it as a challenge. If awkward smelly guy can't ruin the experience for the rest of the players, I think I might have a winner. But, I do make sure I'm in a room with other supportive game designers, and I try to steer clear of playtesting at minor cons where I don't know anybody and where the focus is not on game designers. Having an organizer that really cares about the designer's road to publication is key.

(I've also never "paid to display." I've paid to attend, but I'm not there to advertise or drum up support. That happens best after-hours with a few drinks or after a good new game with friends. And also because I really do enjoy the company.)