Did you ever pay attention to your meal hours during an exhibition? Do you actually eat or just slide around the meal hour with quick snacks? What time of the day do you reach peak number of visitors? Why would all the visitors rush in at the same time? Are the sweets or the crackers preferred most? There is a reason for all this.
The fresh/daily treats you offer gives a definite idea about how you value your customer. It is also considered as a quick energy source, as well as helping focusing and motivation. Always keep in mind that an energetic, well motivated customer always has a high potential of striking a deal.