While most show managers make these visits low key, Meg Smith, Expo Director for the American Sportfishing Association in Alexandria, VA, often tries to become part of the scene. You can read all the trade magazines you want, but you have to get out and see people to find out who you're missing. Networking can also be a vital prospecting tool. Attend business and social events related to your target industry. Join committees and boards.
Most associations provide a directory of members.
Use their meetings to mingle with potential exhibitors and learn enough about target companies to customize your sales pitch. Consider club memberships, too, especially for consumer shows. Even more surprising is how many industry people are in them. It's a great way to get to know people, tell them about what you're doing and get them to join the show. Once you've identified your prospects, it's time to find out all about them, specifically what your prospect needs to buy from you and how to distinguish yourself from the competition.