When a company has a booth at a convention or trade show, it is viewed as a fixture and host to all visitors attending the event. Company employees working in the booth are perceived to be knowledgeable about the event even if they are visitors to the venue city themselves. It is important all employees working in a booth familiarize themselves with the event schedules and amenities such as the location of the restrooms, exits, and food vendors.
Being helpful to a visitor can be wonderful PR for a company. The visitor may not be a potential customer, but they will remember your company name and speak highly of the company in the future.