Are you referring to coupon codes which you can submit during the checkout?
If so, there are three types of codes you can find:
1) There are codes which you get in your email if you subscribe to EdenFantasys Newsletter. These codes are usually sent on special occasions (like Valentine's Day or the Earth Day or Mother's Day or Eden's relocation to Atlanta etc). These codes vary in what you can apply them to (for example, on Mother's Day, as far as I remember, the code was valid only on toys for women), but sometimes the code gives you a discount for the whole order.
2) There are affiliate codes - these are 3-digit codes which give you a 15% discount for your whole order. You can get such a code from another contributor and they will earn a commission if you use it. For example, you can use my code SYN. You can also get your own affiliate code if you activate the Affiliate Program.
3) There are codes which are printed in Eden's Sexis Magazine. Each of them allows you to save some amount of money depending on the value of your order. The codes range from SEXIS10 (giving you a $10 discount if your order is under $50) to SEXIS30 (giving you a $30 discount if your order is over $30). I believe, there are also SEXIS15, SEXIS20 and SEXIS25, but I don't remember exactly - try experimenting with these when you check out.
Hope I did not forget anything I needed to mention.