I have some customers who are insisting that I serve something called a “fry sauce” with my french fries, what exactly are they talking about?

I have some customers who are insisting that I serve something called a “fry sauce” with my french fries, what exactly are they talking about? I think this is a regional thing, having seen it extensively throughout Utah and Idaho.  Fry sauce is a combination of ketchup and mayonnaise, sometimes with an added spike in spicy-ness with Tabasco or dried chili powder, and has the appearance of Thousand Island dressing (for those of us that can remember this pink/salmon colored dressing or the lime green of a Green Goddess dressing). Arctic Circle actually has a 16 ounce bottle that consumers can purchase, see this link: http://www.acburger.com/menu/fry-sauce.html According to Technomic, the favorite dipping sauces for fries and onion rings are: Ketchup 65%, Cheese sauce 27%, Ranch dressing 26%, Honey Mustard 15%, Barbeque sauce 14%, Blue Cheese Dressing 12%, Mustard 10%, Sour Cream 9%, Red Salsa 8%, and Balsamic Vinegar 7%. However, I have to tell you that on Facebook the late night favorite to pair with an order of French fries is a Frosty. Wendy’s even has “Frosty” as a character and people are constantly writing in to rave about dipping fries in the soft ice cream mixture. Certainly not going to win any calorie count wars as nutritious, but apparently it tastes great.