[Richard] McKenzie did a fair amount of real-world research on the popcorn front,
and his most important finding (as far as I’m concerned) is that if
you’re in a cinema which gives you a choice between buying a medium bag
of popcorn and a large tub of popcorn, there’s a greater-than-50%
chance that the medium bag will actually contain more popcorn than the large tub.
That’s from Felix Salmon.