Trade shows operate for a reason,it's not just the window cleaning industry that has one.
I used to exhibit in the furniture show many years ago at the nec,they also had a ceramics show there,there is the caravan show,i would go so far as to say that every trade/industry would have a show in some form or another...are they all a waste of time,i doubt it but they probably have sceptics who cant see past the end of their noses as well.