I have done quite a few trade shows for United First Financial and I have failed miserly at most of them. it is amazing how much you learn from failure. One key principle I try to teach everyone about marketing it to do it right or do not do it at all. This is very true for trade shows.
Booth Size
A small 10′x10′ booth is great if you want to be part of the crowd but if you want to stand out gather a group of people and split the cost of a larger booth.
Electric
Usually very expensive but having power for your booth is a must.
Internet
MUST HAVE! Here you have a few options. You can purchase a wireless internet card from your cell phone carrier for roughly $50 a month. If you are traveling at all to do business this can pay for itself very easily. If you are to purchase on of these air cards I recommend that you get a USB card. It might be a little clunky when using on your laptop but it also allows you to use it on a desktop computer. It is essential you have the ability to run an analysis, show the demo software or sign up and agent at the booth.
Giveaways
You need to create a reason for people #1 to stop at your both and #2 to give you their information. This goes back to doing it right. Factor into the cost of the booth a nice prize of some sort. Maybe a small plasma TV, iPhone or if it is a home show try a few hundred dollar gift certificate to Home Depot.
This is just a few tips but remember your goal is to get their info not for you to give them info. Flyers, business cards and fancy pens end up in the trash on the way out or the next day at home. Do not focus on what you give out but how you captue and follow up.
