This was a great little find. This eyeshadow “base” is not really a primer. It really is used more to even out the lid (if you are using the skin tone one) and creates a smooth surface for your shadow. I think this is an unnecessary step for most people. However, I found a great use for this product. I use it all over my lid –from lash line to brow- the inner corner of my eye and under my eye. I found that when I use it under my eye is smoothies out that area and keeps it hydrated as well. So when I put on my concealer the eye area looks totally smooth. It gets rid of that wrinkly area in the under-eye inner corner and it fills in the shallow lines in the outer corners as well so I get a much smoother, younger looking eye throughout the day. Now, the down side of using this product is that my concealer does not last as long which means that I have to reapply concealer around 2pm-3pm. But (and this is a big one for me) even when I add more concealer, the eye area is still hydrated and smooth, so it does not look like I am caking on concealer. I find that using this base under my eye has really changed the way my overall make-up looks. Because no matter how great your makeup looks on the rest of your face, if it is all dry and cakey under your eyes, the overall look is just yuk. So, despite the hassle of adding concealer mid-day, I am really loving this product. This product comes in a little pot, but I wish it was in a tube instead, so the packaging is not the best. I took off one lippie for the packaging. It does glide on very easily so it does not require tugging or excessive rubbing to apply. I first apply my moisturizer. Then my foundation, then this base. It does not need to “set” like a primer so you can proceed with shadow right away. After that I add my concealer and setting powder. I have sensitive skin, so I will give a new product a few weeks to see if I get a reaction. I have been using this for a little over 2 weeks no, and I have had no reaction or any irritation of any kind. (Of course, if that changes I will update my review). The base sells for about $7 USD anywhere NYX is sold. It comes in this skin tone one that I am using, but it also comes in white and a pearl color. I have not tried those. The skin tone looks dark in the pot but it goes on sheer, so it should work for any skin tone.