if you have multiple credit cards and one of them has an expiration date less than 12 months in the future or one you plan to close, use it for the Den subscription. The renewal will get declined since the card will be expired, and other than a few annoying emails from frontier asking for a different card, you will be fine. The next time after that the Den makes sense again, buy it new with another card about to expire. If you are a typical FT churning cards for deals, you should have a card to make that technique work, and you'll be giving frontier fifty bucks only when its in your interests.