They say all publicity is good. (BP did not think so with the Gulf oil spill, but let that pass.) There may have been no direct new leads from the trade show but, when the video of Alice using the company logo as a club goes viral, the whole world is going to see the company name battering someone senseless. That must be worth something.
I try to seek out those booths. I then engage them in intelligent (at least for my half) conversation. That usually gives me more than enough humourous anecdotes to last me until the next show. It's really a shame they don't realize how ridiculous they sound when they talk. They could make a fortune as stand-up comics :)