There are two types of discount codes you can choose to enable for your own products on Inktale:
Family & Friends Code allows your biggest fans to purchase your work at the product's base price, without any profit margin. This code is unique for each of the artists, and can be switched on and off in My Account → Discount codes section of your account.
Custom Codes allow customers to purchase your products with 10% off. Each code is valid for unlimited purchases, and you can create as many codes as you'd like. Custom codes can be deactivated temporarily by clicking on the lock icon in My Account → Discount codes, or deleted permanently as well.