I noticed over the last few years that when I go to Burger King, there is no small soda on the menu. If you order a small you get what is called a medium on the menu board because it is their smallest size. They sell medium, large, and extra-large (or some similar name).
This struck me as odd, but I realized that it was their way of upsizing the order without having to ask to do it. If they had re-labeled their medium as "small", their large as "medium", and their extra-large as "large", would it have accomplished the same thing? I don't know. Maybe they wanted to limit the number of sizes available to keep things simple, and at the same time upsize some of the orders, and have something to offer for super-sizing.
I don't think a 16 oz soda is necessarily silly, but you might consider calling it a child size or something like that to discourage most people from ordering it. Seems to me that you shouldn't provide drink or popcorn weights/volumes either unless you are asked. Labels like medium, large, and extra-large, are all you need. I think big numbers might discourage some people from buying the larger sizes. I know I've purchased a large soda before and then realized when I received it that it was larger than I really wanted. In that case, many people will simply not drink it all, but they already payed their money. That's good for the seller. The customer shouldn't mind because they knew the cost before they ordered. Hopefully, they will think they got a good deal. Not everybody looks around to see how big a cup is before ordering. A lot of people will focus on the menu board and not see the sample cups that you probably have displayed. Your regulars will know better, but remember many people are not regulars these days.
Seems to me I remember Burney Falls saying she had removed the number of ounces from her drink menu and had replaced it with the simpler small, medium, and large labels. She said it helped sell more soda, and consequently made her more profit. From the per cap figures she has posted in these forums, we should all pay attention to what she is doing at the concession stand.
[This message has been edited by lionheart (edited November 17, 2007).]