Some people use MAC Paint Pots as their eye primer, probably because it is sticky and can enhance the vibrancy of eyeshadows etc. I bought this because my beloved Bare Study Paint Pot dried out and I was in the market for another eyeshadow base.
Why do I need one since I already have a primer? Well… uh… I needed it because it makes eyeshadow appear even more vibrant than on bare skin or only with primer, and NYX Jumbo Pencils tend to crease on me if applied too thickly. MAC Paint Pots have a drier texture, and thus work better for my oily lids.