Thanks to reader Jessica for this tip!
Today only (ends 11:59PM Pacific on 4/26), get 15% off sitewide on the NYX website HERE (excludes sale items and holiday sets). Free shipping on orders $25+. I thought that you needed a code for this, but I just got the email from NYX and I see that the discount is reflected in the item listings. No codes required.
Thanks again for the tip, Jessica!