Across many of the exhibition halls of the world there is a split between stands and displays that choose to hire attractive models and ‘brand ambassadors’ to greet guests and visitors to their booths and those that bring along the experts in their trade to greet and meet so as to be able to explain and inform the passersby more effectively and accurately due to their deep knowledge base with the product. This method is also useful to find out more about how people perceive your product or service, or with more practical exhibitions you can even observe how people naturally use your product or service.
In my experience you want to customise your service to the type of exhibit that you are showing off, specifically you need to determine how complicated or intuitive your intended message is to understand for the ley person. If you have concepts or practical activities that are hard to understand or complicated to use in some manner then you will need to have people on hand that are able to advise with accurate and helpful advice and assistance, examples of this is complex software or hardware, or with a complicated investment scheme for example. In these cases if the staff on hand at the booth are uninformed about the product then people are more likely to leave your booth confused or simply disinterested.
However in cases that you are promoting or selling simple ideas, products or services then you can use less informed and more attractive models from agencies might attract more people to your booth. Of course at this point you have to think about who you will be appealing to with your models and whether they are the target audience for your product. If not you might have a crowded stand which will feel good but you might not convert many of those people to customers.