The way that Zoya words their promotions is pretty ridiculous. Technically, they are saying that you get three free bottles of nail polish, but you have to pay $15 shipping. Come on. It's three bottles for $5 each, which is a decent discount, since they are usually $9. Use code KICK. Full info here.
Zoya is my favorite nail polish brand, and you can see some of their polishes that I like in my Zoya tag.