You Can Use The Same Card Twice
If you have a card that gives you good perks and rewards, you can actually sign up for it twice. If you wait 10-18 months, you can re-apply and get the annual fee waived. This is great for mileage-accruing cards that give big signup bonuses. If you cycle the cards every 10-18 months, you can get 25,000-50,000 bonus points from each card without ever paying the annual fee.