Now with Kixify Select: Authenticity Guaranteed! The World's Largest Sneaker Marketplace. Turn Your Closet Into Cash. Smart, Fast & Easy. Join Millions of Sneakerheads. Buy. Sell. Discover. Money Back Guarantee for Buyers & Sellers. Official KicksOnFire & Paypal Partner. Kixify is a marketplace where people around the world connect, discover, sell and buy unique sneakers.