Categories, tags, and the mayonnaise problem

In one of our local grocery stores, mayonnaise is located in the aisle with salad dressing. In another, mayonnaise is located with condiments (such as ketchup and mustard).

According to Wikipedia, mayonnaise is a condiment. A variety of sources talk about mayonnaise as a base for, but not necessarily being, salad dressings of various sorts.

What intrigues me here is the decision making process of the store managers or, if there is such a thing, the “person who decides what products get placed on what shelf in which aisle” when evaluating where they should shelve mayonnaise in their store.

And, even more so, how they came to these different decisions.