I don't believe this product is a necessity but it is nice to have. It makes applying foundation or BB cream pretty easy, especially when it comes to the areas around the nose and eyes. I also find that I use less product because it helps to spread things evenly.
My only issue is with the price. It's far too expensive for such a simple product. Especially when the likes of Woolies stocking a very similar product at a fraction of the cost and it works just as well.