You invest time, money and energy to create a presence at a trade show, so you can meet prospective customers, and possibly close some sales on the spot. You’ve had a display made to help tell your sales story, and you hope to attract traffic into your space.
Only you’re far less likely to get the visitors you want if you’re sitting down. People are reluctant to intrude on a sitter, rather than approach someone who’s standing. Not only that, when you’re sitting you look low-key and tired, just the opposite of the image you want to project. Yeah, it’s hard to stand for a whole day at a trade show, smiling, looking welcoming, chatting with visitors who may or may not be prospective customers. But that’s why you’re there.
If you need a rest — or a bathroom break — schedule somebody else to man the booth while you’re gone. Somebody to stand on his feet, till you get back.