I've never done any promotional trade or business shows, but believe strongly in having a physical gallery in your storefront, house or shop. It just makes it super easy to sell a particular type of sign when the client can see and feel with their eyes and hands, the real deal. Not every person automatically knows what a carved sign is when you try to explain it to them on the phone or someplace other than your shop.
I'm not even a retail shop but can attest to the value of having a nice gallery of work with a variety of mediums that you work in. This is what I've put together over the years. The wall is 10'h. x 30'w. and showcases, carved, blasted, digital, hand painted, dimensional letters, magnetic and some other oddball stuff.