The "secret sauce (mayonnaise + thousand island dressing)" on/in the In-n-outs is about as Mickey D's as it gets, if you want to go that route. Oh wait, the secret sauce is the same thing between In-n-out and Mickey D's.
I have wondered why a good burger would need a gimmicky cover-up in order to make it good. I blame the Mickey-D's generation for that one.
Now, I'll say it again. To each his own.
Whataburger does use some spices on the patties. They are pretty much like any standard beef rub, although I have yet to make an exact copy of them. Getting close.
I just think putting any type of mayo or mayo-based spread on a burger is blasphemy.
There is no gimmick regarding secret sauce as far as in-n-out burger goes. The term "secret sauce" was a Jack in the box term used in the early 70's. In-N-Out's gimmick is that everything is fresh, no freezers , microwaves. The fries are hand sliced from potatoes daily , not purchased potato puree formed into a fry. All lettuce is hand leafed and tomatoes and onions sliced daily. They do put thousand island on their burgers if you want and they will grill your onions on demand (thousand island and grilled onions is called animal style). You can also order extra patties,.
In-n-Out is a family owned business, there are no franchises to be bought. The people that work there are generally there for keeps. In-n-Out pays their employees very well considering their a burger joint and also provide health care for every employee. I believe a store manager makes somewhere in the 60,000-70,000 range.
You will not find rude, unkept, or kids filling a Summer job working at In-n-Out either. Every person that I have come across working there seem to have their life together. Generally In-n-Out's have 2 drive throughs as well as walk up ordering. I have also never been to a In-n-out that doesn't have both drive ups backed up down the street and the walk up billing out the door and this is true even at midnight. I have eaten a Whataburger in Arizona and though it's a decent burger however it's still the same old burger chain with kids taking orders and cooking with dirty bathrooms. In-n-Out is a spotless place, white and red tile everywhere. There is always 2 people on trash duty so you will never see trash on the ground of tables or a trash can over loaded. I guess what I am trying to say is that In-n-out is a very well oiled machine that offers the public with extreemly fresh burgers and fries in a fast and efficent manner in a place that is clean second to non.