I always read my junk mail. You never know when you'll get a juicy targetted offer not available to the general public. It may be extra cashback on a specific category, or just 0% APR with no balance transfer fees from a bank that usually charges fees. Besides, I have to open it to shred it anyways, and after a while you become a pro at sifting through the fine print instantly.

In this case, I got my Discover Miles card back when it was offering a 5,000 mile signup bonus. Now, it's offering a 12,000 miles bonus over 12 months. I cashed in my bonus miles and have been happily earning 5+% interest on my borrowed free money. But for some reason, ...