I have no idea what this is used for. I tried it on my face, and I got a lot of sparkle, but that's all I can see a difference of. I'm not sure what its function is perse. In my opinion, it's fine for clubbing, or keeping your face looking shiny, or metallic, but not an everyday using product.
Since I received this as a gift from Sephora, I'll continue to use it. However, I wouldn't go out and buy this on my own. I don't see what the great thing about it is!