Quoted from rosh:
so, suggestion for mike, look at partnering smaller vendors in neighboring booths, they can then coordinate break times so their peer can keep an eye on things, since it seems theft is a concern for these one person operations. Maybe they can't sell the wares of their neighbor, but they can help keep things safe and can at least tell attendees when the vendor is expected to be back. Obviously vendors would need to be comfortable with each other, but worth a try vs losing small vendors like Rob and Jeremy.
Fantastic idea! Throw a sheet over the goods and have a vender neighborhood watch! I like it.