Consider the following equations: 
1) Big package = more cereal
2) Small package = less cereal
Typically, you’d expect these equations to hold true, but they don’t, at least not in the supermarkets here. There’s one box of cereal that’s bigger than the others by miles  but it has less cereal than most of the others.
How would you ‘measure’?
By weight. The weight is printed somewhere near the bottom of the box. So, if you were just glancing at prices and box sizes, you would tend to buy the cereal with the bigger box (and attractive packaging).
Here’s the clincher: The biggest box has cereal that’s typically less than half a kilogram . There’s a box that’s smaller than this one but it contains one kilogram of cereal. Double the weight, and yet the package is smaller.
There are other cereal boxes too and they’re smaller in size but similar in weight to the biggest box. Hey, at least the size of the box is commensurate with the weight of the cereal it contains.
Is this clever marketing from the big box cereal company? Maybe the first time, when I’m trying cereals, I may be tricked into buying the big box cereal. When I open the box though, I wouldn’t feel good about being suckered.
Companies try hard to gain your trust for their products. They spend a bunch of money in the process. And then they do something that makes you wary of their product.
Is this a marketing problem, a packaging problem, or a design problem? Or is it simply a problem of expectations–you expect something, you get something else?
Maybe they’re just using Fitt’s law as applied to packaging: The bigger the better.
What do I know? I’m just a customer that they lost.
PS: The big box cereal company remains unnamed for national security reasons.
: Does this make me sound like a scientist or what?
: Yes, I am exaggerating.
: It’s the whole metric thing, it’s approximately a pound.