One is Block Buster, they always ask for mine. My honeys brother's exwife(such a bitch) rented movies on my account(they let her because the last name matched) and kept 6 movies 25 days past the due date so with my account you must have the card and also know the password.
The second is Winn Dixie, the grocery store I shop at. It is not a discount card, they scan the card and the school my boys go to earns a percent of the sales.