When you are ready to do ANY online shopping (including buying a Groupon) be sure to go through Ebates so you can earn cash back on your purchases. There are many "cash back" sites but I prefer this one. (I have averaged over 6% cash back on all of my online purchases for the past 2 months!)
Ebates is a shopping site that gives you up to 26% Cash Back every time you shop online. You can shop at over 1000 stores including eBay, Groupon, JCPenney, Macy's, Nordstrom, Overstock.com, Walmart, Kohl's and Home Depot. Plus you get additional savings with exclusive coupons, free shipping offers, and limited-time sales!
So if you are planning to buy something online anyway- why not earn some cash back on your purchase?