Discover Card is an excellent cash back card when used selectively. However, if you're looking for an annual-fee free card to use for cash back on everyday purchases, the Discover Card is not for you. The 10% - 25% back referenced above is possible only when using the online Shop Discover shopping portal and signing up for Discover's 4th quarter 5% bonus for online purchases.

SO if you're buying something at magazines.com, you can get 20% back through the Shop Discover portal and 5% using your card for an online purchase (4th quarter promotion).

If you're getting your hair cut and want cash back for using the card, you get 0.25% back if I recall -- it's so low that I NEVER use my Discover Card for anything but promotional items.

Discover Card a great card to have in your arsenal, and one that bloggers rarely talk about. However, you really need to be careful with it, and it's definitely not for everyday, run-of-the-mill spending.