Money mediates between signs: like a signifying interpretant, it "fulfills the office of an interpreter". In capitalistic society, money is the necessary interpretant in a signification chain.

Look around you, and you will find that it is possible for every second interpretant to be money. Money manufactures the illusion of a relation of equivalence between itself and other signs. What qualifies money to function as a universal interpretant is its status as a cultural icon.

Repetition is the operating factor in creating a cultural icon. To create a cultural icon we need an iconic sign - a sign similar to the object (real or not) it stands for, and recognizable as a representation of this object by its similarity to it.
The repetition of the iconic sign produces a habit so strong it becomes a cultural icon. In capitalistic society, money's position as a cultural icon has a special attribute.

Unlike other cultural icons, that by way of the sign are significantly tied to the object they stand for, money can stand for pretty much anything.