The latest buzz term "integrated marketing" sounds great: sell the exhibitor an integrated package of marketing products that includes exhibit space, sponsorships, 12x ad frequency in the show's sponsoring magazine (if there is one), banner ads on the web site, etc.
Don't do it. Each sale should be made separately to maximize the revenue generated from the exhibitor. The show sales rep sells them a 20x30. A specialist in sponsorship sales creates a targeted "seize mindshare" package for them. The magazine ad sales rep maintains an on-going relationship with them, while the show ad sales person sells them a cover ad in the show preview and the on-site directory. And finally, the on-line media sales rep sells them a banner ad on the web site. Be sure the exhibitor knows all the available options (and you should coordinate the effort internally).
What if your largest exhibitor demands a total package deal from one dedicated sales person? More on that in future Tips.