40% OFF all purchases.
Just enter promo code SUNNY at checkout and get that discount. Since it's online-only, you should spend the $50 to get the FREE shipping, but in reality it's like spending $90 you'll probably already spend and getting $40 back in your wallet. That's how my head works anyway.
Click here to start shopping at Gap.com. Note: There are some random things not included in the sale, but it's things like kids' uniforms, which I don't think you usually get at Gap anyway.