I've been a member of Ebates for over a year now and have enjoyed getting money back with each purchase I make through the site.
Here's how it works: login and choose from hundreds of popular retailers including Macys, Shopbop, Sephora, Drugstore.com, Victoria's Secret, etc. and click on which store you'd like to shop. They'll redirect you to the store. You'll shop like you normally do and earn a rebate for each purchase. That's it.
Each retailer offers different cash back rates. One of my faves is Beauty.com which offers 6% off. This may not sound like a lot but when you consider that beauty products go on sale, like NEVER, it really comes in handy. Of course you'll get your rebate on top of any sale they're having anyway, and believe me those dollars add up quickly -- I've already gotten back about $350!
There's no coupon code but you must be a registered user. Sign up here and get shopping!