The ideal number is the number YOU want, since the place is yours. This has been discussed here before, some people prefer large selections, others prefer smaller selections. Personally, I would have a smaller selection, for the very reason you suggested, it may slow down your concession line if people take too long to decide. Look at your sales, and see which items don't sell that well, and eliminate them. Eliminate items that are basically the same thing,gummy worms and gummy bears etc...Eliminate ones which you don't make as much money on.
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