Earn 2.4% cashback on completed cruises and 8.0% on Gift Certificate purchases. Please be advised that some travel merchants do not post Petro Rewards until after your trip has been completed. You may notice $0.00 posted to your account as a placeholder. After your trip has been completed this will be replaced with the correct Petro Rewards. Some travel merchants may take up to 60 days after your trip has been completed to post to your account.