In general, your exhibitors want to see power buyers rather than users. A power buyer purchases many units while a user purchases one unit. To cite an IT show as an example, a corporate CIO (power buyer) buys 1000 PCs, while the user buys one PC (for personal use).
You should have a distinct plan to attract power buyers to your show. First, set your own definition (such as "purchases at least 100,000 widgets per year") and then identify by actual name everyone in your community of interest who fits this definition.
Next, set a goal for how many you want to get to the show, such as 40% of the 300 widget power buyers that you have identified. Some suggestions:
Create events/attractions/programs to get them to say, "I must be at Widget Expo." For example, one event could be a private, by-invitation-only reception where they can mingle with their fellow power buyers.
Consider "bribing" them, such as covering part or all of their travel expenses or offering some other perk such as free plane fare for their significant other.
When you do succeed in, for example attracting 112 of the 300 widget power buyers, be sure you translate this into more exhibit revenue next year. Investing $25,000 to attract these 112 power buyers can be easily offset by, for example, selling 50 more booths (equalling $100,000 in additional exhibit revenue).