allmodcons

Not confusing at all. You get 5% cash back rewards on certain categories that change every quarter. The 5% category cash back limit per quarter is $400 in purchases, or $20 in rewards. Cash rewards for purchases outside that quarter's category will get you a fraction of a percent until you have spent a certain amount of money on the card. Not worth it for those purchases outside the quarterly categories. Use another card for those.

5% cash reward is actually limited to $100 in gas & auto maintenance per month. Who cares about the interest rate if you pay it off every month. It is contradictory to want a cash rewards card when you blow it on monthly interest.