4 unique credit card features: Rare perks and surprising restrictions

There is an immense variety of credit cards, but once you zoom in on a specific category, things start to look similar. For example, the top 2% cash-back credit cards vary only slightly in their offerings, whether it's an insurance benefit or redemption option. The benefit of this is that if you understand one card in a category, it's not too difficult to decipher the value provided by the rest. …