Had your chips (or maybe not)

Why do the makers of vending machines always put the crisps at the top?

If anything is going to get stuck on it's way down, it is that bag of crisps that you just had to have. You put your money in, type in the number and half expect them to get stuck on the way down.

Surely some bright spark can come up with the idea that the one item that always gets stuck might be better placed lower down so it has less distance to fall and therefore less chance of getting stuck??

Either that or just make the space between the items and the glass window just half an inch further apart.

Simple.