Paid it off, eh?
Has it broke yet?
All things being equal, credit card companies do want the customer paying interest forever.
I've heard that folks who pay off their bills monthly and carry no balance are frowned upon to the point that they are dropped. I don't know if these are 'free 'cards or they pay a monthly fee. Probably worth finding out what your credit card company likes.
I have an American Express Business card, which is also my Costco membership card. The 4% refund on my daily fill-up at the gas station and the percentage discount on other things I use the card for, everywhere I use it, more than cover the annual fee. The side benefit is that my credit has dramatically improved, having the card.
Might be worth seeing if that plan will work for yourself.