This is my favorite site to shop on. I use it all the time. The prices are fair and all items are good quality. Shipping is free and they have a hassle free return policy.
Groupon customer service is horrible. You can't actually call them, you have to request a call or chat with someone. It is extremely easy to accidentally buy something but very difficult to exchange or refund things. They don't offer that many good deals anyways and I personally will not be using their service again.