In the single barrel thread, Dave Morefield made a comment about the case probably being the "fundamental unit" in the booze business, rather than the bottle. Since the readers of this board love arcane knowledge, I will point out that an even more fundamental unit is the "9 liter case."
What I mean is that a standard 12 bottle case of 750 ml bottles (the standard bottle size) contains 9 liters of product. However, a case of 1 L bottles (the size typically used by bars) contains 12 liters of product, a case of 1.75 L bottles (standard is 6 bottles) contains 10.5 L, and so on. Why is this a problem? Well, if the company states its sales in cases, as they typically do, you would have to know how many of each kind of case they sold in order to accurately determine their sales. Instead, they simply state their sales in 9 liter cases. In other words, they convert the figures for all non-9 liter cases to reflect the number of cases that would have been sold if they were 9 liter cases, so 100 cases of 1.75 L bottles converts to 116.66 9 liter cases, for example.
When you see someone in the liquor business stating case sales, they invariably mean 9 liter cases. Like I said, arcane knowledge.