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This is interesting, and insoluble. I would guess 10,000 times as many people have been to In and Out as Shake Shack (including me). No matter how you do a distribution of preferences you probably can't tell anything because the numbers of samples are so biased. I haven't been to shake shack but have never not enjoyed a burger at In and Out or Five Guys. Throw Burger Joint in the mix though and it's game over.