Today through June 15, 2018, you can transfer your Membership Reward points--the points earned by cards like the Amex Platinum, Business Gold Rewards, and the Blue Business Plus--to Flying Blue and earn a 25% bonus. This means 24,000 Membership Rewards = 30,000 Flying Blue miles, which is enough for a roundtrip between the mainland US and Hawaii in Delta economy, at least if booked before June 1.