When people go to your booth or kiosk at a trade show, they expect to find knowledgeable people working there.
This means, naturally, that anyone who is working at your booth needs to know ALL about your product or service, because if you hire a warm body to hold down the fort while you go to lunch, and a potential customer asks a complicated or technical question that your temp can’t answer, you’ve LOST THAT CUSTOMER!
The moral of the story is this: make sure that everybody who is working your kiosk and therefore representing you and your business, knows everything that can possibly be known about your product or service.
Anything less just isn’t acceptable. Period.