For the next six weeks you'll earn 250 SPG points each time you check in for your stay at a St. Regis, The Luxury Collection, Sheraton, Westin, Le Meridien, Tribute Portfolio, Four Points, or other participating Marriott/SPG hotel through SPG's mobile app.

There is not a cap to how many points you can earn through this promotion, but only check-ins through June 15, 2018 that you booked directly with SPG on its website or in the app will count.

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.