After having my own great experiences with glass ketchup bottles, I decided to observe people at a restaurant
attempting to use them.
It turns out that the process is not completely intuitive, and the instructions are in some cases more cultural knowledge than anything else. For instance, you have to tap the 57 on the neck of the Heinz bottle in order to properly dispense ketchup. Many people, however, try in vain as they turn the bottle upside down, only to get the watery film that had settled on top of the ketchup. Others slap the bottom of the bottle and successfully get ketchup out, but the lack of control in that process causes them to flood their beloved french fries.
A couple notes:
- The last thing people do is read the label. Especially if it's small
- Many restaurants have addressed this problem by, in the case of fast food restaurants, having centralized ketchup dispensers that have built-in pumps
- Squeeze bottles, while less classy, also fix this problem
