Discounts for Online Shopping

I have heard this one a few times, and just started doing it myself. When you go online to shop and find items you are interested in, put the items in your cart and then...wait. As in log out and forget about it for a day or two. More often than not, during that waiting period between putting items in your cart and actually purchasing, the vendor will send an email code for a discount that's anywhere from 25-40% off. It gives the customer incentive to complete their order. This tends to work about 50% of the time.