In addition, Discover offers up to an additional 12 mos. warranty coverage onto any item you purchase with a warranty using your card.
This is a very common perk of using a credit card to make a purchase. American Express and Visa Signature cards also offer this. I haven't researched Mastercard much, but I'm sure their higher-level cards offer something similar.
I did use Discover's purchase protection on a $10 pair of sunglasses that were stepped-on a week after purchasing. I'd never filed a purchase protection claim before, so I did it more to understand the process than for the money. It was pretty easy and only involved about 10 minutes on the phone and a few minutes collecting and emailing the documents necessary to process the claim. I received a check in the mail about two weeks after initially calling in. I'm not sure I'd use it again for a $10 purchase, but I certainly would for $50+.
What I really like about Shop Discover is that, if a retailer is there, the discount is at least 5%. Many times the discounts offered from Chase's Ultimate Rewards are 1-3 extra points per dollar and seem to change regularly. If you have a Discover card and need to make some "Back to School" purchases, definitely check out Shop Discover because many clothing retailers are participating in a promo right now offering 10-15% cash back. I just got a 15% back on an Under Armour order, for instance.