Quoted from Coindork:
they would list the item on eBay for more than your asking price. If the item sold, then they would come back to your booth and try to purchase the item
I admit, I'm having a hard time seeing what's so bad about that scenario. You're there to sell stuff, right? You could have other, direct customers trying to talk you down on price too, right? You're not being forced to sell at a lower price, right?
Seems to me, the person listing your item on eBay and then buying it from you is, at least in some sense, doing you a service. Your item is getting broader advertising that it might have, you didn't have to do any of the work to deal with eBay (and frankly, there are lots of good reasons to appreciate not having to deal with eBay directly), and you got an extra sale at the show that you wouldn't have had otherwise.
Quoted from sataneatscheese:
You may be trying to sell your pin for $2500 if there is a potential buyer in the area that sees the pin for $2200 who are they going to buy it from?
Except there isn't actually a machine available for $2200. Unless you buckle and sell it for less. In which case, you advertised the pin for a higher amount than you thought it was actually worth anyway.
I will grant there's a lot of debate around the idea of "short selling". And some of the concerns are legitimate. And certainly it's not kosher for someone to come take photos of your private residence and post them publicly. But short selling comes with its own risks, and no one's forcing you to participate. If you believe the machine is really worth $2500, then don't sell it for less. The person trying to short your pin will come up, well...short. And you'll still get your pin sold.
I can tell from the posts in this thread that this opinion isn't going to be popular, and I'm sure lots of people will get their shorts twisted over it (no pun intended). The person in this particular example seems to have gone beyond just a simple short, and maybe the moderation was well justified in this case. But the general practice of selling something you aren't actually in possession of quite yet, is a tried and true if risky business practice. And it only works if the owner of the item goes along with it.
So if you don't like it, don't go along with it.