Now that the Amex Rewards Gold is a credit card, Amex have no incentive in place for an upgrade to Platinum. Plus the Platinum bonus cannot be obtained if you have the Gold credit card as both cards are Membership Rewards registered cards. Just had an online chat with Amex to confirm this is the case. Hopefully a new incentive will be put in place, as it's made the Platinum card a lot less attractive if you already hold the Gold credit card.