second question of the week

(prompted by the first question of the week)
...and what is up with the "known as Best Foods west of the Rockies" thing on mayonnaise?

East: Hellman's / West: Best Foods
East: McCormick / West: Schilling
East: Edy's / West: Dreyer's

There must be more, too, that I've forgotten or am not aware of. But it's weird.