I once sold ice cream. We were graded by how many additional items we got customers to add to the ice cream (those cost extra).

Over time, I learned to positively associate certain combinations (graham cracker crust goes well with fruit, for example) and negatively associate others. So, even if I didn't like that particular kind, I could just suggest whatever things people frequently ordered and get a lot of sales.

I was #1 so consistently that my manager took me out of one of the contests to give the other people a shot.