Well the reason is the name.
Before you apply makeup, your skin should be prepped and primed right?
Well, Kim Kardashian’s makeup artist, Mario Dedivanovic seems to think differently.

Good thing Dedivanovic is here to help.
I just like an emollient moisturiser [sic].
I like a good old fashioned emollient moisturiser under makeup" (viaCosmopolitan).

Dedivanovic does, however, use eye primers.
This step will help shimmery shadows, like those the reality star often wears, stay put.
The proof is in the pudding; just look at Kardashian’s makeup flawless, always.
If Kardashian doesn’t need it, well, we probably don’t either!