To find out who attends, ask the show management for a demographic profile of their attendees. Typically, show literature will list only the numbers and general titles of their attendees. Check the titles and purchasing responsibility if that information is available.
Another route to finding the best shows is to contact past attendees. Have a list of questions ready that will tell you if they are indeed the decision makers, and what value they placed on their time spent in the exhibit hall. You can also check out the exhibitor list from the previous year, and ask those non-competing exhibitors what their impressions of the show were and whether they will be attending again. Or, if possible, go to the show as an attendee and walk the exhibit floor so you'll know if you want to attend it next year. You can get an exhibit-only pass for many shows, so you're not paying the entire fee.
You also need to check with the show managers and ask how they are promoting the show and about their strategy for getting people to the exhibit hall. If it's a new show, there has to be very good promotion to get the traffic you need to make it worthwhile. Often, the conference schedules are set up so that luncheons and socials are held in the exhibit hall to ensure that attendees spend time with vendors. While it is nice to get them into the exhibits (and to your booth), food-related functions aren't always the best arenas for talking with prospects, mainly because it's hard to handle a plate of food, a drink, and your company's literature at the same time. Make sure the schedule allows for plenty of time around those events so attendees can eat and visit your booth. If it doesn't, let the show management know so they can plan better the following year. (Or better yet, if it's a show that you do well at, volunteer for the planning committee, if there is one.)
Once you've nailed down the best shows to attend, you need to figure out what you're going to be standing in front of. Next, we'll solve that problem with information on how to design and care for your booth.