I sell Vienna Beef hot dogs & Polish for a living. My customers dress their own hot dogs. I supply all the original Chipico (Vienna Beef) condiments, including mustard and ketchup. Once they pay, it’s theirs to dress. In my business, ketchup is preferred over mustard by 2 to 1. I’m a traditional Chicago baby boomer, where mustard rules. I’ve never had ketchup on a hot dog, however, if you buy a dog from me, use as much of what ever you want to dress it.