Ebates is another site where you can get online shopping discount codes and earn cash back on purchases when you shop through their site.
Personally, this is not my favorite site for rewards, but I have used it three times because the discount code they offered that was exclusive to them, was more cost effective than shopping through a different site and getting the reward. You are supposed to get a $5 credit for signing up and using this site, but I did not get that credit. For the three purchases I made through them, I have a $2.61 credit in my ebates account. They send checks or paypal quarterly to pay you the money, if you have a $5 credit in your account. Again, its not a huge money maker by any means, but I always want the best deal when I shop, so I consider the discount I got on the front end to be the reward.
I think you do get a $5 bonus for referrals that sign up and make a purchase. I haven't ever referred anyone, so I can't verify if this works. The site also says it has "referral" bonuses, so if you reward 500 people you get the $5 per person reward and a $500 bonus. Sounds great, but I can guarantee I don't know 500 people who want to sign up for this, LOL!
I used them at Christmas to get the kids some stuff from Disney and they had exclusive discount codes for $$ off and free shipping. It offered 3% cash back, and is currently showing 7% cash back. If you shop frequently online, this may be more profitable for you than it has been for me. Regardless, it is a resource to check for discount codes and free shipping before you buy. Just remember you have to click through their site as a member for the codes and discounts to work.