I don't think Gideon is 100% correct. I bought an Asus tablet from groupon and was thinking about exchanging it and dealt with groupon, not a seller. I didn't even know groupon had third party sellers.
If it is from Groupon directly beware that if anything is wrong with it they don't do exchanges, only returns. At least that was the case with the tablet I got. I'm also not sure if they come with warranties. I got a scuff mark on the corner of my screen that was barely noticeable but bothered me enough to contact them. I was told I could only return it.
I'd say it's only worth it if you're saving a significant amount of money.