Shopping Cart Coupons

Here is a trick I learned from some websites. I didn't do this intentionally, I just put things in a cart and daydream about them, well on Sigma I had put things in a cart and just clicked out of it and days later they sent me a coupon.
If you put things in a cart and you are logged in into that account and you just put item(s) in it, and you don't purchase it just yet, click out of it, they will send you a coupon via email in a week or so with a 5%-20% coupon depending what website you had your item(s) This isn't all websites just some. Bonus right there.