There are several types of base coats available to consumers. I always recommend getting one to suit the health of your nail. If your nails are dry or brittle use one that says rehydrating the nail bed, or use one that says, you know, strengthen the nail if you know your nails are weak.
Keep in mind that base coat is a barrier between your natural nail and the nail polish. If you're using a dark polish like this what happens is the pigment from the nail polish actually turns your natural nail yellow. The base coat creates a barrier between your nail and the dark nail polish. And thinking about it this way, if it's on your natural nail, you want it to work and rehydrate your nail or make it stronger, because your nails are porous.
I would recommend always using a base coat that is thin, because you don't want it to take a long time to dry. I also recommend that you use a base coat or ridge filler base coat. Ridge filler base coats do exactly what it says - they fill the ridges in your nail. As it dries, it literally coats the nail so that you wouldn't see the ripples in the finger as you apply the nail polish. It gives it a more smooth and natural look.
Not only is base coat awesome for protecting your nail between the nail polish it also almost acts like an anchor to the nail polish. It goes on first, it helps the nail polish adhere to your nail bed, and it'll make your manicure last longer.
Here's an example as to why you should apply base coat. This nail doesn't have base coat on it, and, as you can see, this one does. Just by looking at the bottle and looking at the nails you can tell that the one with base coat shows the true color of the nail polish versus the one without base coat.