What is the transparent sticky substance that you find at the back of your credit card when it first comes?

It is at the back of the credit card or any cards that you first get. It affixes the credit card to the cardboard that comes in the envelope from the bank.

Payment to credit card company lost in the mail. What to do?

My credit card payment was due October 6; balance was $500. Minimum payment is $15. I use my credit card for EVERYTHING so I can earn points, but I pay off the balance in full each month. I always pay on time or early, but never late.
Until this month. On Sept [...]