When I was young I was walking outside nearby by myself and I noticed a [vending] machine the made coffee on the street. I asked a person if the cups should be larger while not containing too much caffiene. He asked me why. "Toplina" [Warmth.] (This was during winter in Bulgaria.)

The next thing I asked him is: How much energy does it take to boil a bit more water anyway?

And I was right. Until adding a certain amount of water to a pan for example which me and my mother tried by boiling water and timing it afterward there is a peak and then a fall (meaning that the time gets exponentially longer to boil the water.)

So you see. Aside from all the business reasons. Winter and I were a small part of the reason for this. [In Bulgaria]

Post Scriptum:

The last thing I told my mother is: Sugar is small. Ground instant coffee is small. The vending machine doesn't have water in it: It comes through a pipe in the ground. The only thing we would have to change is replace milk with something that takes up less space.. Cream.

Post Post Scriptum: The last and final thing I asked her is if the larger portion would prevent the ingredients from spoiling. She replied "Coffee and sugar can't spoil."